Nova

A nova was a star's dramatic increase in brightness over a relatively short period of time.

In 2267, the USS Enterprise (NCC-1701), which was trapped in the universe of superspace, discovered that a nearby star was about to go nova. To ensure that the resulting energy discharge would be sufficient to return the ship to its own universe, Captain James T. Kirk had the mind module of a war machine fired directly into the nova, accelerating the star's collapse into a black hole.