logarithm relative energy output proton proton pp cno triple fusion processes different temperatures dashed line shows combined energy generation pp cno processes within star sun 's core temperature pp process efficient '''stellar nucleosynthesis''' creation nucleosynthesis chemical elements nuclear fusion reactions within stars stellar nucleosynthesis occurred since original creation hydrogen helium lithium big bang predictive theory yields accurate estimates observed abundances elements explains observed abundances
Natural science Space science Stellar astrophysics Stellar nucleosynthesis