The Clash of Light and Darkness

The Clash of Light and Darkness, also known as M33 X-7, is a black hole binary system and the most massive such system known in Triangulum, with a total combined mass of 85.7 solar masses. The system consists of a stellar-mass black hole and a companion O-type giant star, which orbit each other with a period of 3.45 days. Due to the mass of the companion star, it will eventually collapse into a black hole as well, creating a binary black hole system. There are no planets in this system, of course.

I'll let Minmus add any fictional details...although just like Romano's Star, there seem to be no nearby inhabited systems.

Development notes
SevenSpheres originally added this system into CelWP as a separate download between Release 1 and 2, based on Luke's stc for it. The Minmus Derp then gave it its proper name in Release 10. Credit goes to Vision and Cham for the ssc effects used, and nussun for her star texture generator that was used to make the texture for the blue giant star.