Red giant stars are still fusing hydrogen in their cores, but are running low on hydrogen. This causes the outer layers of the star to expand and cool, making the star appear red and giant. Once the hydrogen is completely exhausted, the star will enter a new phase of fusion and begin fusing helium in its core.

Solved

Red Giant Stars Are

Question 40

Multiple Choice

Red giant stars are

A) close to exhausting their supply of hydrogen.
B) have already exhausted their supply of hydrogen.
C) are close to exhausting their supply of helium.
D) have already exhausted their supply of helium.

Correct Answer: