Naked singularity

A naked singularity is a singularity that causes a deviation in space and time. In 2270, Starfleet detected a naked singularity forming in the Beta Quadrant, and dispatched Commander Spock and the USS Enterprise to investigate. After spending six weeks orbiting the singularity, it began to close in on itself, and to date is the only naked singularity to be encountered by Starfleet.

In an alternate version of these events, Spock discovered that the singularity would later expand to destroy the universe within 100 years. (TOS novel: The Entropy Effect).