‘Death Spiral’ Around a Black Hole Yields Tantalizing Evidence of an Event Horizon:

“The Hubble telescope may have, for the first time, provided direct evidence for the existence of black
holes by observing how matter disappears when it falls beyond the “event horizon,” the boundary
between a black hole and the outside universe. Astronomers found their evidence by watching the
fading and disappearance of pulses of ultraviolet light from clumps of hot gas swirling around a massive,
compact object called Cygnus XR-1. This activity suggests that the hot gas fell into a black hole.” Clicking on the image will send you to an animation of how matter falling into the black hole might look.Space Telescope Science Institute