Black cluster

A black cluster is a type of cluster which is created when multiple protostars collapsed in close proximity to one another. The result of this was an area that absorbs energy and affects starships navigational systems. The clusters were also known for their violent and unpredictable gravitational wavefronts. (Star Trek CCG: Premiere)

In 2367, the SS Vico was assigned to chart a black cluster in Sector 97. After contact was lost with the Vico, the USS Enterprise-D was sent into the area to investigate. (TNG episode: "Hero Worship")