Cygnus-XL was a black hole, and the final star in the sequence that revealed the location of Belkov's missing feldon crystals. Locking the panels of Orbiter onto Cygnus XL pulled the ship towards the black hole.

Cygnus X-1, a powerful X-ray source with a supergiant companion, is a possible black hole in the constellation of Cygnus. (D: Games)