How do fusion affect the life of a star?
1 Answer
Fusion reactions define the life of a star.
Explanation:
When stars form, their cores are hot enough to start Hydrogen fusion which produces Helium.
What happens when the supply of Hydrogen runs out depends on the mass of the star.
Smaller stars, like our Sun, undergo core collapse when the Hydrogen runs out. They start Hydrogen fusion in the layers surrounding the core which causes the star to expand into a red giant. Then Helium fusion starts producing Carbon and Oxygen. Once the Helium is exhausted the star can't get hot enough to continue fusion reactions and becomes a white dwarf.
Larger stars seamlessly start Helium fusion, then Carbon fusion and fusion of heavier elements. Once the core becomes mainly Iron, fusion is no longer possible. At this point the star usually explodes as its core collapses into a neutron star or a black hole.
