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26 Cards in this Set

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