Stars don't last forever. Occasionally, a star bigger than our Sun will end its life in a huge explosion, called a supernova.

This explosion happens because the center, or core, of the star heats up very fast. The outer layers of the star are blown off in the explosion. The shock waves and material that fly out from the supernova can cause the formation of new stars.

Supernovae last one or two years, and can shine brighter than a whole galaxy for this time. There are many beautiful pictures of the gas clouds remaining after supernovae.

What happens to the star after the supernova depends on how big it was to begin with. If the star was only a little bigger than the Sun, the core will shrink into a tiny neutron star only a few miles across. If the star was much bigger than the Sun, the core will shrink down to a black hole.