Black holes may be invisible, but their surroundings aren't — and for the first time, astronomers have directly measured a superheated "corona" encircling one of these cosmic giants.
The supermassive black hole, RX J1131, sits about 6 billion light-years from Earth and spins at more than half the speed of light. While the monster itself remains hidden, it gorges on nearby gas and dust, heating it to millions of degrees and blazing as a quasar — one of the brightest objects in the universe. Its corona, a halo of superheated gas, spans about 50 astronomical units, about the size of our solar system.
