The Life Cycle of a Star

Question 1

What is the life cycle of a star that is about the same size as our sun?

Extra info in brackets

Answer 1

1.) Cloud of gas and dust are drawn together by gravity.
2.) (Particles move more: Temperature rises) –> protostar
3.) (Hydrogen nuclei join to form helium nuclei) main sequence star. –> main sequence star.
4.) Hydrogen runs out (fusion force is less than inward gravity force) so star collapses.
5.) Collapse increases temp –> helium fuses together to create heavier elements.
6.) Star expands –> red giant.
7.) Star stops fusing helium –> shrinks becomes white dwarf.
8.) White dwarf cools down (no fusion happening) - becomes a black dwarf.

Question 2

What is the life cycle of a star that is much bigger than our sun?

Answer 2

1.) Once the stars run out of hydrogen, they expand into “red super giants.”
2.) Red super giant explodes to form a “supernova.”
3.) Temperature of supernova is high enough to produce elements heavier than iron.

Question 3

What ONLY stage of the life cycle of a star can produce elements heavier than iron?

Answer 3

• The supernova stage is the only stage that produces elements heavier than iron.

Question 4

What happens to the elements that are produced from the exploding supernova?

Answer 4

• The elements are distributed throughout the universe.

Question 5

What two objects can a supernova form?

Answer 5

1.) A neutron star.
2.) A black hole.