What is the difference between a nova and a supernova?

A nova and a supernova are both astronomical events that involve the explosion of a star. However, there are some key differences between the two.

Nova

A nova occurs when a white dwarf star in a binary system pulls material from its companion star. As this material accumulates on the surface of the white dwarf, it becomes extremely hot and dense, eventually triggering a runaway nuclear reaction that causes a sudden increase in brightness. The star can brighten by up to a million times its original brightness, but it does not completely destroy the star.

Supernova

A supernova, on the other hand, occurs when a star has burned through all of its nuclear fuel and collapses under its own gravity, causing a catastrophic explosion. This explosion can be so bright that it briefly outshines the entire galaxy it is in, and can produce as much energy as the sun will produce in its entire lifetime. A supernova can completely destroy the star.

So, the main difference between a nova and a supernova is that a nova is a much smaller explosion that does not completely destroy the star, while a supernova is a much larger explosion that can completely destroy the star.