Astronomers are surprised as a hungry black hole ‘switches on’

A supermassive black hole feasting on nearby matter produced one of the brightest transient events, which was one of the most spectacular "switching on" phenomena ever observed.

The transient J221951, which is fueled by a greedy black hole, is one of the brightest transients ever seen. Transients are astronomical phenomena or objects that change in radiance over brief periods of time. A supermassive black hole would be expected to be located exactly where the black hole is now, at the center of a previously noticed galaxy. But the precise cause of the transient event seen in J221951 is still a mystery to astronomers.

The supermassive black hole's nature is currently unknown, but it's possible that J221951 is a star that got too close to the black hole and was violently torn apart by tidal forces brought on by its enormous gravity, a process known as spaghettification. 

This phenomenon, known as a tidal disruption event (TDE), would result in some of the stellar debris from the shattered star falling to the black hole's surface while other material was directed to the black hole's poles before being ejected at nearly light speed, generating intense electromagnetic radiation. 

The black hole in question could be producing this bright transient event through a variety of mechanisms, including the spaghettification of an unfortunate star. J221951 may also be the result of a galaxy's central nucleus transforming from a dormant to an active state.