Why does the CNO cycle not occur in low-mass stars?
A) Low-mass stars do not have enough carbon, nitrogen, and oxygen.
B) Low-mass stars do not live long enough to reach this stage.
C) Low-mass stars do not have high enough temperatures in their cores.
D) Low-mass stars do not have enough convection to cycle elements.

Question

Quizplus · Accepted Answer

The CNO cycle requires very high temperatures to occur, typically over 15 million degrees Celsius. Low-mass stars, like the Sun, have core temperatures that are lower, around 15 million degrees or less, which are not sufficient to initiate the CNO cycle as the dominant process of hydrogen fusion. Instead, these stars primarily fuse hydrogen into helium via the proton-proton chain reaction, which requires lower temperatures.

Why Does the CNO Cycle Not Occur in Low-Mass Stars