Newly Discovered Secondary Supermassive Black Holes Challenge Astrophysics Theories

Astronomers have detected a burst of light from the smaller of two supermassive black holes within the blazar OJ 287, marking the first time the smaller black hole's direct emissions have been observed. The smaller black hole orbits the larger one every 12 years, passing through its accretion disk twice in that period, releasing bursts of light that last about a fortnight. The system is one of the few cases where there are good prospects for detecting gravitational waves from their mutual orbits.