Powerhouse

A black hole steals gas from a giant companion star in this artist's concept of Cygnus X-1, one of the first black holes discovered. The hot gas forms a superhot disk around the black hole. The disk emits enormous amounts of X-rays (inset, X-ray image from Chandra X-Ray Observatory). A recent study found that Cygnus X-1 is about 6,000 light-years away. The black hole is 15 times the mass of the Sun, and it spins about 800 times per second. [ESA/Hubble; inset: NASA/CXC]