It's a popular misconception that black holes behave like cosmic vacuum cleaners, ravenously sucking up any matter in their surroundings. In reality, only stuff that passes beyond the event horizon—including light—is swallowed up and can't escape, although black holes are also messy eaters. That means that part of an object's matter is actually ejected out in a powerful jet.
If that object is a star, the process of being shredded (or "spaghettified") by the powerful gravitational forces of a black hole occurs outside the event horizon, and part of the star's original mass is ejected violently outward. This in turn can form a rotating ring of matter (aka an accretion disk) around the black hole that emits powerful X-rays and visible light. Those jets are one way astronomers can indirectly infer the presence of a black hole. Now astronomers have recorded the final death throes of a star being shredded by a supermassive black hole in just such a "tidal disruption event" (TDE), described in a new paper published in the journal Monthly Notices of the Royal Astronomical Society.
"The idea of a black hole 'sucking in' a nearby star sounds like science fiction. But this is exactly what happens in a tidal disruption event," said co-author Matt Nicholl of the University of Birmingham. "We were able to investigate in detail what happens when a star is eaten by such a monster."