Researchers have spent the past few years watching a black hole re-awaken roughly 300 million light-years away from Earth.

While solitary black holes should be common, they are hard to find. The one in Sagittarius revealed itself when it passed in front of a dim background star, magnifying the star’s light and slowly ...

Long after the black hole in the center of a ... a viable candidate for the largest light echo ever discovered. "This object covers a large area in the sky, which makes it a bit easier to get ...

While sifting out signatures of supernova remnants, a high-schooler stumbled upon the afterglow of a dormant black hole. It may be one of the largest ever seen.

First, the outer boundary of these cosmic titans is a one-way light-trapping surface called an event horizon, the point at which a black hole's gravity is so powerful that not even light can escape.