where is most of the sun's energy produced
Sun The core of the Sun extends from the center to about 20–25% of the solar radius.[78] It has a density of up to 7005150000000000000♠150 g/cm3[79][80] (about 150 times the density of water) and a temperature of close to 15.7 million kelvins (K).[80] By contrast, the Sun's surface temperature is approximately 5,800 K. Recent analysis of SOHO mission data favors a faster rotation rate in the core than in the radiative zone above.[78] Through most of the Sun's life, energy has been produced by nuclear fusion in the core region through a series of steps called the p–p (proton–proton) chain; this process converts hydrogen into helium.[81] Only 0.8% of the energy generated in the Sun comes from the CNO cycle, though this proportion is expected to increase as the Sun becomes older.[82]