When does a supernova occur?

A supernova is the explosion of a star -- the largest explosion that takes place in space. A supernova is the explosion of a star -- the largest explosion that takes place in space. read more

Since a supernova can occur whenever the mass of the star at the time of core collapse is low enough not to cause complete fallback to a black hole, any massive star may result in a supernova if it loses enough mass before core collapse occurs. read more

On average, a supernova will occur about once every 50 years in a galaxy the size of the Milky Way. Put another way, a star explodes every second or so somewhere in the universe, and some of those aren't too far from Earth. read more