Nova

A nova was the explosion which brought a star's life to an end. So powerful was the blast that it could destroy nearby planets. For instance, Benny and a group of her students had barely left Perfection when it was destroyed by its exploding sun in 2593. (PROSE: Oh No It Isn't!) When novas were of an extraordinary magnitude, they were called supernovas.

In 1644, the nova of a star in the constellation of Orion was visible on Earth. Indeed, the Seventh Doctor and Ace went to Marsham Castle for a commemorative viewing of the event. (PROSE: Nightshade)

The Doctor was occasionally responsible for the destruction of stars, as when his eighth incarnation intentionally made Crivello's sun go nova, in order to simultaneously destroy the Threshold and a large Dalek contingent. (COMIC: Fire and Brimstone)

On other occasions, the Time Lords themselves interfered with the lives of stars. When the stars in the constellation Zeta Cancri threatened to collide, and then go nova, the Chronarchs dispatched K9 to avert such an outcome. The Time Lords took such an exceptional interventionist stance because they reasoned that three stars going nova in such close proximity would result in the destruction of the galaxy. (PROSE: K9 and the Zeta Rescue)