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39 Cards in this Set

  • Front
  • Back
What do the remains of a supernova become?
a neutron star
How can you tell a star's temperature?
by its color
What is all of space and everything in it called?
What can giants and super giants blow up into?
What happens to the largest supernovas when they collapse?
they become black holes
What is a light year?
the distance that light travels in one year
Is a light year a unit of distance or time?
a unit of distance
What do astronomers use to measure distances to nearby stars?
What is parallax?
The apparent change in position of an object when you look at it from different places.
What are the main characteristics used to classify stars?
size, temperature, and brightness
What are very large stars called?
giant stars or supergiant stars
What are two important characteristics of stars?
temperature and absolute magnitude
What is the diagonal line formed by most of the stars in the H-R diagram called?
the main sequence
In the main sequence, does surface temperature increase or decrease as brightness increases?
surface temperature increases as brightness increases
What is nuclear fusion?
The process in which hydrogen atoms in the stars combine to for helium and release energy.
In nuclear fsion hydrogen atoms combine with what to release energy?
What is the nebula?
a swirling cloud of dust and gas
As stars run out of fuel they expand to form what?
red giants and supergiants
The remains of the largest supernovas collapse and become what?
black holes
What is formed when gravity forces the dust and gases of a nebula together?
a protostar
What is so strong in a black hole that even light cannot escape?
True or false? Small and medium stars will become supernovas?
What gas is fuel for stars?
A star's brightness as if it were a standard distance is called its what?
absolute magnitude
A huge group of stars, such as the Milky Way, is called what?
a galaxy
The unit used to measure distances between stars is a what?
a light year
The region of the Hertzsprung-Russell diagram with the most stars is called the what?
main sequence
A graph of stars showing temperature on the X-axis and brightness on the Y-axis is called a what?
Hertzsprung-Russell (H-R) diagram
What is used to determine the distance to nearby stars?
The brightness of a star as seen from Earth is called its what?
apparent magnitude
Because of its large size, the star Aldebaran is often called a what?
giant star
How do all stars begin?
as part of a nebula
What is a nebula?
a large cloud of dust and gas swirling in space
What forces dust and gases together to form a protostar?
What does the length of a star's life depend upon?
its mass
Do stars with less mass live longer? Why?
Yes because they use their fuel more slowly
What happens when stars rn out of fuel? What is formed?
The center shrinks but the outer part expands forming red giants or supergiants
What do small and medium stars (white dwarfs) become when they stop glowing?
black dwarfs
White-dwarfs will become black dwars when they stop doing what?