Kugelblitz

A Schwarzschild kugelblitz (German: "ball lightning") is a concentration of heat, light or radiation so intense that its energy forms an event horizon of a black hole and becomes self-trapped. It could be created by a massive amount of energy concentrated into a small space, such as that produced by a gamma-ray burst. This extremely intense gravitational field generates temperatures in excess of a billion degrees.

Kugelblitz drives are used in black hole starship engines.