carbon burning

Carbon burning is fusion of two carbon nuclei, which takes place in early stars, producing magnesium and other elements including neon, sodium and oxygen. A carbon-burning shell appears in a sufficiently-massive star during a phase while in the asymptotic giant branch (AGB), forming after the helium-burning shell and before further such shells. According to one such model, with sufficient temperature, the neon-burning shell would form next. Carbon burning requires a temperature on the order of 5 × 10⁸ K.