silicon burning

Silicon burning is essentially the latter part of the alpha process, from silicon on. (The alpha process consists of helium nuclei fusing with heavier nuclei, each time forming a nucleus of an element with atomic number two higher.) Elements up to iron, nickel, and zinc. are synthesized. Silicon burning takes place in a sufficiently-massive star during a phase while in the asymptotic giant branch (AGB), forming after an oxygen-burning shell has started (according to one common model), and after the temperature has risen to about 2 × 10⁹ K. It is said to last on the order of a day, after which a core collapse occurs (possibly with a core collapse supernova), leaving a neutron star or stellar-mass black hole.