Stars between 0.4 and 4 solar masses go through two distinct red-giant stages.

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Stars between 0.4 and 4 solar masses go through a red-giant phase when they exhaust the hydrogen fuel in their core, then contract and heat up before fusing helium in their core and expanding again into a more luminous and extended red-giant phase. This can happen twice for these stars as they repeat the contraction and fusion process with heavier elements, known as the asymptotic giant branch phase.

Stars Between 0