Supernova

A supernova is the catastrophic explosion of a star, one of the universe's most violent and luminous events. For a brief period—sometimes just weeks—a single supernova can outshine an entire galaxy containing billions of stars. These cosmic detonations occur when a star reaches the end of its life, either by suddenly collapsing inward and rebounding, or by accumulating matter from a companion star until it becomes unstable.

Supernovae serve as cosmic laboratories and distance markers. They forge heavy elements like iron and nickel, scattering them across space to seed new worlds. Astronomers use certain types as "standard candles" to measure cosmic distances, helping map the universe itself. The observations that earned the 2011 Nobel Prize in Physics revealed that the universe's expansion is accelerating—a discovery made possible by studying distant supernovae.

A white dwarf in a binary system can trigger one type; the collapse of a massive star's core triggers another. Either way, the aftermath enriches space with the building blocks of planets and life, making supernovae essential to cosmic history.

Related

Star Death, Neutron Star, Black Hole, Cosmic Rays, Stellar Evolution, Observational Astronomy