Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
26 Cards in this Set
- Front
- 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
|
