Absolute Brightness a measure of the total light is produced in a star in a given second Absolute Magnitude the magnitude a star would have if it were exactly 10 parsecs away one measure of absolute brightness Absorption the destruction of a photon - the energy causes an electron to jump a higher excited state Absorption Nebula a nebula which is visible because it blocks light from a background source also known as a Dust Lane Absorption Spectrum a spectra with dark lines against a continuum background Acceleration a change in a bodies speed or direction of motion Accretion Disk a disk of material associated with mass transfer in a binary star system Active Galactic Nucleus a galaxy with a nucleus which is emitting a large fraction if the energy in the system Active Regions regions surrounding Sunspots which have strong magnetic fields Algol Problem the problem of having a low mass star in a more advanced evolutionary state than a high mass star in a binary system caused by mass transfer changing a star's evolution Alpha Particle a high energy helium nucleus produced in a nuclear reaction Apparent Brightness a measure of how much light an observer actually sees Apparent Magnitude one measure of the apparent brightness of a star Association a set of very young stars found in the same region of the sky Assymptotic Branch the region in the HR diagram where stars have an inert Carbon Core and two shells of Helium and Hydrogen burning Atom the smallest part of an element that keeps the property of that element consisting of an nucleus with protons and neutrons and electrons Atomic Epoch the time in the electrons combined with nuclei to form atoms- the time that created the 3K background radiation Atomic Number the total number of protons inside the nucleus of an atom Atomic Weight the total number of protons and neutrons inside the nucleus of an atom Background Radiation the 3K microwave radiation created in the early universe Barred Spiral Galaxies a class of spiral galaxies with a central bars Beta Radiation radiation consisting of Beta particles Beta particle a high energy electron creating in a nuclear reaction Big Bang the idea that the universe expanded from a point about 10 billion years ago Binary Pulsar a pulsar in a binary star system - sometimes used for testing theories of gravity Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Absolute Magnitude the magnitude a star would have if it were exactly 10 parsecs away one measure of absolute brightness Absorption the destruction of a photon - the energy causes an electron to jump a higher excited state Absorption Nebula a nebula which is visible because it blocks light from a background source also known as a Dust Lane Absorption Spectrum a spectra with dark lines against a continuum background Acceleration a change in a bodies speed or direction of motion Accretion Disk a disk of material associated with mass transfer in a binary star system Active Galactic Nucleus a galaxy with a nucleus which is emitting a large fraction if the energy in the system Active Regions regions surrounding Sunspots which have strong magnetic fields Algol Problem the problem of having a low mass star in a more advanced evolutionary state than a high mass star in a binary system caused by mass transfer changing a star's evolution Alpha Particle a high energy helium nucleus produced in a nuclear reaction Apparent Brightness a measure of how much light an observer actually sees Apparent Magnitude one measure of the apparent brightness of a star Association a set of very young stars found in the same region of the sky Assymptotic Branch the region in the HR diagram where stars have an inert Carbon Core and two shells of Helium and Hydrogen burning Atom the smallest part of an element that keeps the property of that element consisting of an nucleus with protons and neutrons and electrons Atomic Epoch the time in the electrons combined with nuclei to form atoms- the time that created the 3K background radiation Atomic Number the total number of protons inside the nucleus of an atom Atomic Weight the total number of protons and neutrons inside the nucleus of an atom Background Radiation the 3K microwave radiation created in the early universe Barred Spiral Galaxies a class of spiral galaxies with a central bars Beta Radiation radiation consisting of Beta particles Beta particle a high energy electron creating in a nuclear reaction Big Bang the idea that the universe expanded from a point about 10 billion years ago Binary Pulsar a pulsar in a binary star system - sometimes used for testing theories of gravity Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Absorption the destruction of a photon - the energy causes an electron to jump a higher excited state Absorption Nebula a nebula which is visible because it blocks light from a background source also known as a Dust Lane Absorption Spectrum a spectra with dark lines against a continuum background Acceleration a change in a bodies speed or direction of motion Accretion Disk a disk of material associated with mass transfer in a binary star system Active Galactic Nucleus a galaxy with a nucleus which is emitting a large fraction if the energy in the system Active Regions regions surrounding Sunspots which have strong magnetic fields Algol Problem the problem of having a low mass star in a more advanced evolutionary state than a high mass star in a binary system caused by mass transfer changing a star's evolution Alpha Particle a high energy helium nucleus produced in a nuclear reaction Apparent Brightness a measure of how much light an observer actually sees Apparent Magnitude one measure of the apparent brightness of a star Association a set of very young stars found in the same region of the sky Assymptotic Branch the region in the HR diagram where stars have an inert Carbon Core and two shells of Helium and Hydrogen burning Atom the smallest part of an element that keeps the property of that element consisting of an nucleus with protons and neutrons and electrons Atomic Epoch the time in the electrons combined with nuclei to form atoms- the time that created the 3K background radiation Atomic Number the total number of protons inside the nucleus of an atom Atomic Weight the total number of protons and neutrons inside the nucleus of an atom Background Radiation the 3K microwave radiation created in the early universe Barred Spiral Galaxies a class of spiral galaxies with a central bars Beta Radiation radiation consisting of Beta particles Beta particle a high energy electron creating in a nuclear reaction Big Bang the idea that the universe expanded from a point about 10 billion years ago Binary Pulsar a pulsar in a binary star system - sometimes used for testing theories of gravity Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Absorption Nebula a nebula which is visible because it blocks light from a background source also known as a Dust Lane Absorption Spectrum a spectra with dark lines against a continuum background Acceleration a change in a bodies speed or direction of motion Accretion Disk a disk of material associated with mass transfer in a binary star system Active Galactic Nucleus a galaxy with a nucleus which is emitting a large fraction if the energy in the system Active Regions regions surrounding Sunspots which have strong magnetic fields Algol Problem the problem of having a low mass star in a more advanced evolutionary state than a high mass star in a binary system caused by mass transfer changing a star's evolution Alpha Particle a high energy helium nucleus produced in a nuclear reaction Apparent Brightness a measure of how much light an observer actually sees Apparent Magnitude one measure of the apparent brightness of a star Association a set of very young stars found in the same region of the sky Assymptotic Branch the region in the HR diagram where stars have an inert Carbon Core and two shells of Helium and Hydrogen burning Atom the smallest part of an element that keeps the property of that element consisting of an nucleus with protons and neutrons and electrons Atomic Epoch the time in the electrons combined with nuclei to form atoms- the time that created the 3K background radiation Atomic Number the total number of protons inside the nucleus of an atom Atomic Weight the total number of protons and neutrons inside the nucleus of an atom Background Radiation the 3K microwave radiation created in the early universe Barred Spiral Galaxies a class of spiral galaxies with a central bars Beta Radiation radiation consisting of Beta particles Beta particle a high energy electron creating in a nuclear reaction Big Bang the idea that the universe expanded from a point about 10 billion years ago Binary Pulsar a pulsar in a binary star system - sometimes used for testing theories of gravity Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Absorption Spectrum a spectra with dark lines against a continuum background Acceleration a change in a bodies speed or direction of motion Accretion Disk a disk of material associated with mass transfer in a binary star system Active Galactic Nucleus a galaxy with a nucleus which is emitting a large fraction if the energy in the system Active Regions regions surrounding Sunspots which have strong magnetic fields Algol Problem the problem of having a low mass star in a more advanced evolutionary state than a high mass star in a binary system caused by mass transfer changing a star's evolution Alpha Particle a high energy helium nucleus produced in a nuclear reaction Apparent Brightness a measure of how much light an observer actually sees Apparent Magnitude one measure of the apparent brightness of a star Association a set of very young stars found in the same region of the sky Assymptotic Branch the region in the HR diagram where stars have an inert Carbon Core and two shells of Helium and Hydrogen burning Atom the smallest part of an element that keeps the property of that element consisting of an nucleus with protons and neutrons and electrons Atomic Epoch the time in the electrons combined with nuclei to form atoms- the time that created the 3K background radiation Atomic Number the total number of protons inside the nucleus of an atom Atomic Weight the total number of protons and neutrons inside the nucleus of an atom Background Radiation the 3K microwave radiation created in the early universe Barred Spiral Galaxies a class of spiral galaxies with a central bars Beta Radiation radiation consisting of Beta particles Beta particle a high energy electron creating in a nuclear reaction Big Bang the idea that the universe expanded from a point about 10 billion years ago Binary Pulsar a pulsar in a binary star system - sometimes used for testing theories of gravity Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Acceleration a change in a bodies speed or direction of motion Accretion Disk a disk of material associated with mass transfer in a binary star system Active Galactic Nucleus a galaxy with a nucleus which is emitting a large fraction if the energy in the system Active Regions regions surrounding Sunspots which have strong magnetic fields Algol Problem the problem of having a low mass star in a more advanced evolutionary state than a high mass star in a binary system caused by mass transfer changing a star's evolution Alpha Particle a high energy helium nucleus produced in a nuclear reaction Apparent Brightness a measure of how much light an observer actually sees Apparent Magnitude one measure of the apparent brightness of a star Association a set of very young stars found in the same region of the sky Assymptotic Branch the region in the HR diagram where stars have an inert Carbon Core and two shells of Helium and Hydrogen burning Atom the smallest part of an element that keeps the property of that element consisting of an nucleus with protons and neutrons and electrons Atomic Epoch the time in the electrons combined with nuclei to form atoms- the time that created the 3K background radiation Atomic Number the total number of protons inside the nucleus of an atom Atomic Weight the total number of protons and neutrons inside the nucleus of an atom Background Radiation the 3K microwave radiation created in the early universe Barred Spiral Galaxies a class of spiral galaxies with a central bars Beta Radiation radiation consisting of Beta particles Beta particle a high energy electron creating in a nuclear reaction Big Bang the idea that the universe expanded from a point about 10 billion years ago Binary Pulsar a pulsar in a binary star system - sometimes used for testing theories of gravity Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Accretion Disk a disk of material associated with mass transfer in a binary star system Active Galactic Nucleus a galaxy with a nucleus which is emitting a large fraction if the energy in the system Active Regions regions surrounding Sunspots which have strong magnetic fields Algol Problem the problem of having a low mass star in a more advanced evolutionary state than a high mass star in a binary system caused by mass transfer changing a star's evolution Alpha Particle a high energy helium nucleus produced in a nuclear reaction Apparent Brightness a measure of how much light an observer actually sees Apparent Magnitude one measure of the apparent brightness of a star Association a set of very young stars found in the same region of the sky Assymptotic Branch the region in the HR diagram where stars have an inert Carbon Core and two shells of Helium and Hydrogen burning Atom the smallest part of an element that keeps the property of that element consisting of an nucleus with protons and neutrons and electrons Atomic Epoch the time in the electrons combined with nuclei to form atoms- the time that created the 3K background radiation Atomic Number the total number of protons inside the nucleus of an atom Atomic Weight the total number of protons and neutrons inside the nucleus of an atom Background Radiation the 3K microwave radiation created in the early universe Barred Spiral Galaxies a class of spiral galaxies with a central bars Beta Radiation radiation consisting of Beta particles Beta particle a high energy electron creating in a nuclear reaction Big Bang the idea that the universe expanded from a point about 10 billion years ago Binary Pulsar a pulsar in a binary star system - sometimes used for testing theories of gravity Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Active Galactic Nucleus a galaxy with a nucleus which is emitting a large fraction if the energy in the system Active Regions regions surrounding Sunspots which have strong magnetic fields Algol Problem the problem of having a low mass star in a more advanced evolutionary state than a high mass star in a binary system caused by mass transfer changing a star's evolution Alpha Particle a high energy helium nucleus produced in a nuclear reaction Apparent Brightness a measure of how much light an observer actually sees Apparent Magnitude one measure of the apparent brightness of a star Association a set of very young stars found in the same region of the sky Assymptotic Branch the region in the HR diagram where stars have an inert Carbon Core and two shells of Helium and Hydrogen burning Atom the smallest part of an element that keeps the property of that element consisting of an nucleus with protons and neutrons and electrons Atomic Epoch the time in the electrons combined with nuclei to form atoms- the time that created the 3K background radiation Atomic Number the total number of protons inside the nucleus of an atom Atomic Weight the total number of protons and neutrons inside the nucleus of an atom Background Radiation the 3K microwave radiation created in the early universe Barred Spiral Galaxies a class of spiral galaxies with a central bars Beta Radiation radiation consisting of Beta particles Beta particle a high energy electron creating in a nuclear reaction Big Bang the idea that the universe expanded from a point about 10 billion years ago Binary Pulsar a pulsar in a binary star system - sometimes used for testing theories of gravity Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Active Regions regions surrounding Sunspots which have strong magnetic fields Algol Problem the problem of having a low mass star in a more advanced evolutionary state than a high mass star in a binary system caused by mass transfer changing a star's evolution Alpha Particle a high energy helium nucleus produced in a nuclear reaction Apparent Brightness a measure of how much light an observer actually sees Apparent Magnitude one measure of the apparent brightness of a star Association a set of very young stars found in the same region of the sky Assymptotic Branch the region in the HR diagram where stars have an inert Carbon Core and two shells of Helium and Hydrogen burning Atom the smallest part of an element that keeps the property of that element consisting of an nucleus with protons and neutrons and electrons Atomic Epoch the time in the electrons combined with nuclei to form atoms- the time that created the 3K background radiation Atomic Number the total number of protons inside the nucleus of an atom Atomic Weight the total number of protons and neutrons inside the nucleus of an atom Background Radiation the 3K microwave radiation created in the early universe Barred Spiral Galaxies a class of spiral galaxies with a central bars Beta Radiation radiation consisting of Beta particles Beta particle a high energy electron creating in a nuclear reaction Big Bang the idea that the universe expanded from a point about 10 billion years ago Binary Pulsar a pulsar in a binary star system - sometimes used for testing theories of gravity Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Algol Problem the problem of having a low mass star in a more advanced evolutionary state than a high mass star in a binary system caused by mass transfer changing a star's evolution Alpha Particle a high energy helium nucleus produced in a nuclear reaction Apparent Brightness a measure of how much light an observer actually sees Apparent Magnitude one measure of the apparent brightness of a star Association a set of very young stars found in the same region of the sky Assymptotic Branch the region in the HR diagram where stars have an inert Carbon Core and two shells of Helium and Hydrogen burning Atom the smallest part of an element that keeps the property of that element consisting of an nucleus with protons and neutrons and electrons Atomic Epoch the time in the electrons combined with nuclei to form atoms- the time that created the 3K background radiation Atomic Number the total number of protons inside the nucleus of an atom Atomic Weight the total number of protons and neutrons inside the nucleus of an atom Background Radiation the 3K microwave radiation created in the early universe Barred Spiral Galaxies a class of spiral galaxies with a central bars Beta Radiation radiation consisting of Beta particles Beta particle a high energy electron creating in a nuclear reaction Big Bang the idea that the universe expanded from a point about 10 billion years ago Binary Pulsar a pulsar in a binary star system - sometimes used for testing theories of gravity Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Alpha Particle a high energy helium nucleus produced in a nuclear reaction Apparent Brightness a measure of how much light an observer actually sees Apparent Magnitude one measure of the apparent brightness of a star Association a set of very young stars found in the same region of the sky Assymptotic Branch the region in the HR diagram where stars have an inert Carbon Core and two shells of Helium and Hydrogen burning Atom the smallest part of an element that keeps the property of that element consisting of an nucleus with protons and neutrons and electrons Atomic Epoch the time in the electrons combined with nuclei to form atoms- the time that created the 3K background radiation Atomic Number the total number of protons inside the nucleus of an atom Atomic Weight the total number of protons and neutrons inside the nucleus of an atom Background Radiation the 3K microwave radiation created in the early universe Barred Spiral Galaxies a class of spiral galaxies with a central bars Beta Radiation radiation consisting of Beta particles Beta particle a high energy electron creating in a nuclear reaction Big Bang the idea that the universe expanded from a point about 10 billion years ago Binary Pulsar a pulsar in a binary star system - sometimes used for testing theories of gravity Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Apparent Brightness a measure of how much light an observer actually sees Apparent Magnitude one measure of the apparent brightness of a star Association a set of very young stars found in the same region of the sky Assymptotic Branch the region in the HR diagram where stars have an inert Carbon Core and two shells of Helium and Hydrogen burning Atom the smallest part of an element that keeps the property of that element consisting of an nucleus with protons and neutrons and electrons Atomic Epoch the time in the electrons combined with nuclei to form atoms- the time that created the 3K background radiation Atomic Number the total number of protons inside the nucleus of an atom Atomic Weight the total number of protons and neutrons inside the nucleus of an atom Background Radiation the 3K microwave radiation created in the early universe Barred Spiral Galaxies a class of spiral galaxies with a central bars Beta Radiation radiation consisting of Beta particles Beta particle a high energy electron creating in a nuclear reaction Big Bang the idea that the universe expanded from a point about 10 billion years ago Binary Pulsar a pulsar in a binary star system - sometimes used for testing theories of gravity Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Apparent Magnitude one measure of the apparent brightness of a star Association a set of very young stars found in the same region of the sky Assymptotic Branch the region in the HR diagram where stars have an inert Carbon Core and two shells of Helium and Hydrogen burning Atom the smallest part of an element that keeps the property of that element consisting of an nucleus with protons and neutrons and electrons Atomic Epoch the time in the electrons combined with nuclei to form atoms- the time that created the 3K background radiation Atomic Number the total number of protons inside the nucleus of an atom Atomic Weight the total number of protons and neutrons inside the nucleus of an atom Background Radiation the 3K microwave radiation created in the early universe Barred Spiral Galaxies a class of spiral galaxies with a central bars Beta Radiation radiation consisting of Beta particles Beta particle a high energy electron creating in a nuclear reaction Big Bang the idea that the universe expanded from a point about 10 billion years ago Binary Pulsar a pulsar in a binary star system - sometimes used for testing theories of gravity Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Association a set of very young stars found in the same region of the sky Assymptotic Branch the region in the HR diagram where stars have an inert Carbon Core and two shells of Helium and Hydrogen burning Atom the smallest part of an element that keeps the property of that element consisting of an nucleus with protons and neutrons and electrons Atomic Epoch the time in the electrons combined with nuclei to form atoms- the time that created the 3K background radiation Atomic Number the total number of protons inside the nucleus of an atom Atomic Weight the total number of protons and neutrons inside the nucleus of an atom Background Radiation the 3K microwave radiation created in the early universe Barred Spiral Galaxies a class of spiral galaxies with a central bars Beta Radiation radiation consisting of Beta particles Beta particle a high energy electron creating in a nuclear reaction Big Bang the idea that the universe expanded from a point about 10 billion years ago Binary Pulsar a pulsar in a binary star system - sometimes used for testing theories of gravity Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Assymptotic Branch the region in the HR diagram where stars have an inert Carbon Core and two shells of Helium and Hydrogen burning Atom the smallest part of an element that keeps the property of that element consisting of an nucleus with protons and neutrons and electrons Atomic Epoch the time in the electrons combined with nuclei to form atoms- the time that created the 3K background radiation Atomic Number the total number of protons inside the nucleus of an atom Atomic Weight the total number of protons and neutrons inside the nucleus of an atom Background Radiation the 3K microwave radiation created in the early universe Barred Spiral Galaxies a class of spiral galaxies with a central bars Beta Radiation radiation consisting of Beta particles Beta particle a high energy electron creating in a nuclear reaction Big Bang the idea that the universe expanded from a point about 10 billion years ago Binary Pulsar a pulsar in a binary star system - sometimes used for testing theories of gravity Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Atom the smallest part of an element that keeps the property of that element consisting of an nucleus with protons and neutrons and electrons Atomic Epoch the time in the electrons combined with nuclei to form atoms- the time that created the 3K background radiation Atomic Number the total number of protons inside the nucleus of an atom Atomic Weight the total number of protons and neutrons inside the nucleus of an atom Background Radiation the 3K microwave radiation created in the early universe Barred Spiral Galaxies a class of spiral galaxies with a central bars Beta Radiation radiation consisting of Beta particles Beta particle a high energy electron creating in a nuclear reaction Big Bang the idea that the universe expanded from a point about 10 billion years ago Binary Pulsar a pulsar in a binary star system - sometimes used for testing theories of gravity Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Atomic Epoch the time in the electrons combined with nuclei to form atoms- the time that created the 3K background radiation Atomic Number the total number of protons inside the nucleus of an atom Atomic Weight the total number of protons and neutrons inside the nucleus of an atom Background Radiation the 3K microwave radiation created in the early universe Barred Spiral Galaxies a class of spiral galaxies with a central bars Beta Radiation radiation consisting of Beta particles Beta particle a high energy electron creating in a nuclear reaction Big Bang the idea that the universe expanded from a point about 10 billion years ago Binary Pulsar a pulsar in a binary star system - sometimes used for testing theories of gravity Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Atomic Number the total number of protons inside the nucleus of an atom Atomic Weight the total number of protons and neutrons inside the nucleus of an atom Background Radiation the 3K microwave radiation created in the early universe Barred Spiral Galaxies a class of spiral galaxies with a central bars Beta Radiation radiation consisting of Beta particles Beta particle a high energy electron creating in a nuclear reaction Big Bang the idea that the universe expanded from a point about 10 billion years ago Binary Pulsar a pulsar in a binary star system - sometimes used for testing theories of gravity Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Atomic Weight the total number of protons and neutrons inside the nucleus of an atom Background Radiation the 3K microwave radiation created in the early universe Barred Spiral Galaxies a class of spiral galaxies with a central bars Beta Radiation radiation consisting of Beta particles Beta particle a high energy electron creating in a nuclear reaction Big Bang the idea that the universe expanded from a point about 10 billion years ago Binary Pulsar a pulsar in a binary star system - sometimes used for testing theories of gravity Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Background Radiation the 3K microwave radiation created in the early universe Barred Spiral Galaxies a class of spiral galaxies with a central bars Beta Radiation radiation consisting of Beta particles Beta particle a high energy electron creating in a nuclear reaction Big Bang the idea that the universe expanded from a point about 10 billion years ago Binary Pulsar a pulsar in a binary star system - sometimes used for testing theories of gravity Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Barred Spiral Galaxies a class of spiral galaxies with a central bars Beta Radiation radiation consisting of Beta particles Beta particle a high energy electron creating in a nuclear reaction Big Bang the idea that the universe expanded from a point about 10 billion years ago Binary Pulsar a pulsar in a binary star system - sometimes used for testing theories of gravity Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Beta Radiation radiation consisting of Beta particles Beta particle a high energy electron creating in a nuclear reaction Big Bang the idea that the universe expanded from a point about 10 billion years ago Binary Pulsar a pulsar in a binary star system - sometimes used for testing theories of gravity Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Beta particle a high energy electron creating in a nuclear reaction Big Bang the idea that the universe expanded from a point about 10 billion years ago Binary Pulsar a pulsar in a binary star system - sometimes used for testing theories of gravity Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Big Bang the idea that the universe expanded from a point about 10 billion years ago Binary Pulsar a pulsar in a binary star system - sometimes used for testing theories of gravity Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Binary Pulsar a pulsar in a binary star system - sometimes used for testing theories of gravity Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Binary Star a set of two stars which are orbiting around their common center of gravity Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Binary Star Evolution the altering of stellar evolution by mass transfer Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Biological Evolution the evolution of living systems from simple to complex Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Bipolar flow an outflow of material in two opposite directions usually associated with T-Tauri stars Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Black Hole a star so dense that its gravity prevents light from escaping from its surface Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Blue Shift a Doppler shift from an object approaching from the observer - the spectra is shifted toward shorter wavelengths Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Brown Dwarf a type of star which never has Thermonuclear Burning in its Core Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Bulge see Galactic Bulge COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
COBE cosmic background explorer satellite - a NASA satellite used to investigate the cosmic background radiation Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Carbon an element which is composed of a nucleus with 6 protons and usually 6 neutrons Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Carbon Detonation Supernova the explosion of a white dwarf when its mass exceeds the Chandrasakhar limit Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Cataclysmic Variables a star which has rapid and unpredictable changes in brightness associated with a binary star system Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Celestial Equator the imaginary line in the sky exactly half way between the North Celestial Pole and the South Celestial Pole Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Cepheid Variables a type of pulsing variable stars where the period of oscillation is proportional to the average absolute magnitude Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Chandrasakhar Limit the maximum mass an object supported by degenerate electron pressure can be before it collapses see also Supernova Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Chemical Evolution the evolution of complex chemical from simple atoms Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Chromosphere a narrow region (3000 km thick) immediately outside the photosphere where the temperature decreases Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Circumpolar a star or object which never rises or sets - it always remains above the horizon - determined by its declination and the latitude of the observer Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Close Universe a universe which will stop expanding, and eventually collapse Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Clusters of Galaxies a group of 5 to 1000 galaxies bound by their common gravity Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Color Index the ratio of blue light to red light one method to estimate the temperature of a star Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Constellation a region in the sky - there are a total of 88 constellations covering every region in the sky Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Continuum see Continuum Spectrum Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Continuum Spectrum a spectra without spectral lines Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Convection see Convective Transport Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Convection Cells regions hot material rising to the solar surface from convection Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Convection Zone a region inside a star where energy is transported through convective transport Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Convective Transport moving energy by moving material - hot material rises and cool material sinks Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Core the region inside a star where nuclear reactions are occuring Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy galaxy
Core-Halo Galaxy a galaxy with an active galactic nucleus which emits radio energy at is nucleus and in a halo surround the galaxy
Corona the hot (1 million K), outer layer of the Sun's atmosphere Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Cosmic Background Radiation the 3K thermal radiation detected from the early universe Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Cosmic Evolution the evolution of the universe Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Cosmological Constant a constant which may change the age of the universe Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Cosmological Priniciple a statement that postulates the universe is the same everywhere Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Cosmology the study of the structure of the universe Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Cultural Evolution the evolution of culture leading towards civilization Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Dark Matter matter which does not emit detectable amounts of electromagnetic radiation see also missing mass Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Deceleration Constant a constant related to the rate the Hubble expansion is slowing Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Declination a measure of how far an object is above or below the Celestial Equator - measured in degrees - similar to latitude on Earth Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Density the amount of mass in a given volume Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Distance Ladder the set of methods used to determine the distance to distant astronomical objects Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Doppler the scientist who discovered the Doppler effect Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Doppler Effect a change in wavelength of detected light caused by relative motion between the observer and the source of the light Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Doppler Shift see Doppler Effect Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Dust Clouds a region in the ISM which is obscured by dust - often associated with molecular clouds Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Dust Grain a small pin-point sized piece of carbon-rich material found in the ISM Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Dust Lane a dark region in the interstellar medium caused by a Dust Cloud which can be seen against a bright background Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Earth our Planet, the third planet from the Sun mostly harmless Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Electromagnetic Radiation the type of energy caused by photons Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Electron a negatively charged particle which is usually found in orbitals around the nucleus of an atom Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Electron Orbital discrete energy levels where electrons are found around a nucleus Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Element a substance composed of a single type of atom Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Elliptical Galaxies a class of galaxies with not disks, little rotation, which is composed of old stars Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Emission the creation of a photon by an atom occurs when an electron jumps from an excited state to an orbital with lower energy Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Emission Nebula a nebula which is visible because it is being ionized from the ultraviolet light of hot, young stars Emission Spectrum a spectra with bright spectral lines
Emission Spectrum a spectra with bright spectral lines