Little black hole orbits large black hole

NASA published this animation showing a little black hole (150m solar masses) whirling around a large black hole (18bn solar masses), punching through its accretion disc like an energetic puppy doing donuts through a bead curtain.

Two massive black holes are locked in a dance at the center of the OJ 287 galaxy. The larger black hole is surrounded by disk of gas; it is also orbited by a smaller black hole that collides with the disk, producing a flare brighter than 1 trillion stars. But because the system's complex physics affects the smaller black hole's orbit, the flares occur irregularly. Scientists used NASA's Spitzer Space Telescope to detect one of these bright flashes on July 31, 2019, confirming that they can now anticipate the timing of these flares to within four hours using a detailed model of the system.