supernova, Astronomy, General

Related Category: Astronomy, General

supernova, a massive star in the latter stages of stellar evolution that suddenly contracts and then explodes, increasing its energy output as much as a billionfold. Supernovas are the principal distributors of heavy elements throughout the universe; all elements heavier than iron are produced in supernovas. Supernovas are the principal heat source for interstellar matter and may be a source of cosmic rays.