Type Ia Supernova

Type Ia supernovae are thermonuclear explosions caused by an ignition of white dwarfs that exceed a fixed critical mass. These white dwarfs are usually in a binary system, where they accrete matter from their companion up to the point of structural instability. The white dwarf then undergoes a runaway reaction, resulting in a supernova and releasing copious amounts of energy that obliterates the initial system.

Type Ia supernovae produces a consistent peak brightness because of this fixed critical mass at which a white dwarf will explode. This makes them excellent candidates as standard candles to measure distances in, and ultimately the age of, the Universe. The explosion also creates abundantly the isotope nickel-56 which decays to cobalt-56 and finally to the stable iron-56. Most of the iron in the Universe is created from Type Ia supernovae.