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26 Cards in this Set
- Front
- Back
What percent of stars are main sequence stars?
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90%
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What is so dense that nothing can escape its gravity field?
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A black hole
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What is produced when the outer layer of a star explodes after the core collapses?
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Supernova
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Why do the positions of the constellations appear to change throughout the year?
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The earth revolves around the sun.
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What is the brightest star in the night sky?
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Sirius
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Why makes Sirius the brightest star in the night sky?
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Its apparent magnitude
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What is used to measure the distances to nearby stars?
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Parallax
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The intense magnetic field assiciated with sunspots may cause huge arching columns of gas called ________________.
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prominences
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What type of gallaxy has the shape similar to a football?
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elliptical galaxy
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How does the sun produce energy?
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by fusing hydrogen into helium in its core
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What are dark cooler areas on the sun's surface called?
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sunspots
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After the core collapses then heats up for a main sequence star what happens to the outer layer?
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it expands
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After a medium star uses up all of its hydrogen what happens to the core?
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it collapses
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Where do we receive light from?
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photosphere
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Where does the sun rotate faster?
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its faster at its equator than at its poles
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What are two or more stars revolving around one another?
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Binary system
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What percent of all of the matting in our solar system is in the sun?
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99%
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What are less common then the other two galaxies?
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Irregular galaxies
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What determines the final stage of a large size star?
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The size of the core
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What is the last life stage of a small star?
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Brown dwarf
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When does a giant star become a white dwarf star?
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after it uses up the helium in its core
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What is used to classify stars based on their absolute magnitude?
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H-R diagram
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What color are the hottest brightest stars in the main sequence?
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blue
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What color are the coolest stars in the sky?
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red
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What kind of star's energy is produced by fusion of helium to iron in its core?
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a super giant star
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When a star is in the main sequence, how does it produce energy?
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by fusing hydrogen to helium in its core
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