Stellar Nucleosynthesis

Stellar nucleosynthesis is the theory describing how the chemical elements heavier than hydrogen and helium are produced through nuclear fusion reactions occurring inside the cores of stars over the course of their lives, and, for the very heaviest elements, in the extreme conditions of a star's explosive death. The theory reached its modern, comprehensive form chiefly through a landmark 1957 paper, commonly known by the initials of its authors as B2FH, written by astronomers Margaret Burbidge and Geoffrey Burbidge together with physicists William Fowler and Fred Hoyle, synthesizing and substantially extending earlier, more limited work by several other researchers into a single coherent framework. The theory explains that stars fuse light elements into progressively heavier ones across their lifetimes, with a star's own mass determining how far up the periodic table this fusion process can proceed before the star exhausts its nuclear fuel, while elements heavier than iron are instead produced primarily through rapid neutron-capture processes that occur during a supernova explosion or, as later research established, during the collision of two neutron stars. Stellar nucleosynthesis is considered one of the most experimentally and observationally well-supported theories in modern astrophysics, since it correctly explains the observed relative abundance of the different chemical elements found throughout the universe.