A nova is a transient event different than a supernova. Should hydrogen accumulate on the surface of a white dwarf star (via mass transfer from a companion star), the hydrogen can ignite and explode in a runaway thermonuclear reaction. The resulting outburst—known as a nova—can exhibit a brightness increase of 10 orders of magnitude, an intensity difference of 10 thousand! However, the star itself is not destroyed. In fact, it’s possible for the same star to have recurring novae. (Supernovae on the other hand completely obliterate their progenitor.)
In the Milky Way, roughly 40 novae are estimated to occur each year, though only about 10 are discovered. Occasionally, these will even achieve naked eye visibility.
* Spotted with the naked eye