CNO

Carbon-Nitrogen-Oxygen

Stellar evolution Fusion
CNO cycle

Catalysed fusion reactions by which stars convert hydrogen to helium

The CNO cycle is one of the two known sets of fusion reactions by which stars convert hydrogen to helium, the other being the proton–proton chain reaction. Unlike the latter, the CNO cycle is a catalytic cycle. It is hypothesized to be dominant in stars that are more than 1.3 times as massive as the Sun.

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