When does a star experience helium fusion?
A)when it is on the horizontal branch
B)after it has become a red giant star
C)just before it enters the main sequence
D)before it leaves the main sequence

Question

Quizplus · Accepted Answer

Helium fusion occurs when a star is on the horizontal branch, after it has expanded into a red giant and the core temperature is high enough to fuse helium into carbon.

When Does a Star Experience Helium Fusion