“Put two ships in the open sea, without wind or tide, and, at last, they will come together. Throw two planets into space, and they will fall one on the other. Place two enemies in the midst of a crowd, and they will inevitably meet; it is a fatality, a question of time; that is all.” -Jules Verne
When any object passes too close to the event horizon of a black hole, the tidal forces acting on it can become so strong that they’ll tear the entire object apart in a spaghettification disaster. While most of the matter will get ejected from the encounter, a significant fraction can be accreted, absorbed and used to fuel the black hole’s growth.
These tidal disruption events have been seen numerous times since the launch of our X-ray observatories, and are now known to come in a wide variety of magnitudes, at a variety of distances and to last a variable amount of time. So when you see the largest, longest-lasting one ever, you sit up and take notice! That’s exactly what’s happened with XJ1500+154, which is now in its second decade of X-ray signals.