Life Cycle Of Stars Flashcards
What is a star?
A star is a massive, luminous sphere of plasma held together by gravity.
What is the life cycle of a star determined by?
The mass of the star determines its life cycle.
True or False: Stars are born in nebulae.
True
What is the first stage of a star’s life cycle?
The first stage is the formation of a protostar.
What is a protostar?
A protostar is a young star that is still gathering mass from its parent molecular cloud.
What process powers a star?
Nuclear fusion powers a star.
What is the main element that stars fuse in their cores?
Hydrogen
What stage comes after the main sequence in a star’s life cycle?
The red giant phase.
What is a red giant?
A red giant is a large, luminous star that has exhausted the hydrogen in its core.
What happens to a star after the red giant phase?
It sheds its outer layers to form a planetary nebula.
What is a planetary nebula?
A planetary nebula is a shell of gas and dust ejected from a red giant star.
What is the final stage in the life cycle of a low-mass star?
The star becomes a white dwarf.
What is a white dwarf?
A white dwarf is a small, dense remnant of a low-mass star that has exhausted all its nuclear fuel.
What is the fate of a high-mass star at the end of its life cycle?
It undergoes a supernova explosion.
What is a supernova?
A supernova is a stellar explosion that briefly outshines an entire galaxy.
What can result from a supernova explosion?
A neutron star or a black hole can result from a supernova explosion.
True or False: All stars end their lives as black holes.
False
What is a neutron star?
A neutron star is the collapsed core of a massive star after a supernova explosion.
What is a black hole?
A black hole is a region of spacetime where gravity is so strong that nothing, not even light, can escape.
What is the Chandrasekhar limit?
The Chandrasekhar limit is the maximum mass of a stable white dwarf star.
What can happen if a white dwarf exceeds the Chandrasekhar limit?
It can undergo a supernova explosion as a Type Ia supernova.
How are elements heavier than iron formed in the universe?
They are formed in supernova explosions.
What is a main sequence star?
A main sequence star is a star in the stable phase of its life cycle, fusing hydrogen into helium in its core.
What is a brown dwarf?
A brown dwarf is a substellar object that is not massive enough to sustain nuclear fusion in its core.
