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29 Cards in this Set
- Front
- Back
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Asterism |
A prominent pattern or group of stars, typically having a popular name but smaller than a constellation |
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Black hole |
A region of space having a gravitational field so intense that no matter or radiation can escape |
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Main sequence star |
Any star that is fusing hydrogen in its core and has a stable balance of outward pressure from core nuclear fusion and gravitational forces pushing inward |
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Neutron star |
A celestial object of very small radius and very high density, composed predominantly of closely packed neutrons |
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Nuclear fusion reaction |
A reaction where two atomic nuclei fuse together to create a larger nucleus and in the process release energy |
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Parallax |
The effect whereby the position or direction of an object appears to differ when viewed from different positions |
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Red giant |
A very large star of high luminosity and low surface temperature |
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Star |
A fixed luminous point in the night sky that is a large, remote incandescent body like the sun |
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Supernova |
A star that suddenly increases greatly in brightness because of a catastrophic explosion that ejects most of its mass |
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White dwarf |
A small very dense star that is typically the size of a planet |
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Binary star |
A system of two stars in which one star revolves around the other or both revolve around a common center |
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Dwarf galaxy |
A small, dim galaxy, intermediate in size between a regular galaxy and a globular cluster |
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Elliptical galaxy |
A type of galaxy having an approximately ellipsoidal shape and a smooth, nearly featureless brightness profile |
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Galaxy |
A system of millions or billions of stars, together with gas and dust, held together by gravitational attraction |
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Globular cluster |
A large compact spherical star cluster, typically of old stars in the outer regions of a galaxy |
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Irregular galaxy |
A galaxy that does not have the clearly defined shape and structure of typical elliptical, lenticular, or spiral galaxy |
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Milky Way Galaxy |
The galaxy of which the sun and the solar system are a part and which contains the myriads of stars that create the light |
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Open cluster |
A relatively loose grouping of stars |
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Spiral arm |
Sites of ongoing star formation and are brighter than the surrounding disc because of the young, hot OB stars that inhabit them |
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Spiral galaxy |
A galaxy in which the stars and gas clouds are concentrated mainly in one or more spiral arms |
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Star cluster |
A group of stars that share a common origin and are gravitationally bound for some length of time |
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Star system |
A large number of stars with a perceptible structure |
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Big Bang Theory |
The universe originated billions of years ago in an explosion from a single point of nearly infinite energy density |
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Cosmology |
The science of the origin and development of the universe |
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Dark energy |
A theoretical repulsive force that counteracts gravity and causes the universe to expand at an accelerating rate |
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Dark matter |
Nonluminous material that is postulated to exist in space and that could take any of several forms including weakly interacting particles or high-energy randomly moving particles created soon after the Big Bang |
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Doppler Effect |
An increase (or decrease) in the frequency of sound, light, or other waves as the source and observer move toward (or away from) each other |
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Redshift |
The displacement of spectral lines toward longer wavelengths in radiation from distant galaxies and celestial objects |
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Universe |
All existing matter and space considered as a whole |
