Galaxy OJ 287 hosts one of the largest black holes ever found — over 18 billion times the mass of our Sun. Orbiting this behmoth is another massive black hole.
Twice every 12 years, the smaller black hole crashes through the enormous disk of gas surrounding its larger companion, creating a flash of light brighter than a trillion stars.
The flares occur extremely irregularly because the physics of this double black hole system is complex.
Scientists have modeled the system accurately enough to predict the timing of the flares to within 4 hours.
Black Hole Orbit in Center of Galaxy OJ 287
Scientists confirmed their model was correct by observing a flare on July 31, 2019 with the Spitzer Space Telescope.
No other telescope (on Earth or in space) was positioned to see the flare when it went off.
NASA Jet Propulsion Laboratory
California Institute of Technology
