Oxygen burning (${}^{16}\mathrm{O}+{}^{16}\mathrm{O}⟶{}^{28}\mathrm{Si}+\alpha$)

Oxygen fusion in sufficiently hot evolved stellar cores has several reaction channels, including the displayed silicon-plus-alpha channel and channels producing phosphorus and protons. Its ashes feed silicon burning, while stellar neutrino energy loss strongly affects the evolution timescale.