Astronomy Photo of the Day

This is an illustration, not a photo, but quite nifty. It's credited to April Hobart of the Chandra X-ray Observatory.

In the center of a swirling whirlpool of hot gas is likely a beast that has never been seen directly: a black hole. Studies of the bright light emitted by the swirling gas frequently indicate not only that a black hole is present, but also likely attributes. The gas surrounding GRO J1655-40, for example, has been found to display an unusual flickering at a rate of 450 times a ...