What happens when a red giant star becomes a white dwarf?

1 Answer
May 25, 2016

A star becomes a white dwarf when fusion reaction stop.

Explanation:

I red giant star is fusing hydrogen and helium to make mainly carbon and oxygen. When the fuel runs out and the star is less than about 8 times that of the sun, it is not possible to generate enough heat to start carbon fusion. At that point the star is mainly oxygen and carbon and collapses into ta white dwarf. It no longer produces energy from fusion reactions.