UPSC 2013 CDS 2 GK Paper

The main source of energy in Sun is nuclear fusion. The energyfrom the Sun- both heat and light energy - originates from a nuclearfusion process that is occurring inside the core of the Sun. Thespecific type of fusion that occurs inside of the Sun is known asproton-proton fusion. Inside the core of sun, nuclear fusion ofhydrogen nuclei into helium takes place.