Milky Way's 'Lurking, Dormant Monster' --"Our Central Black Hole Currently Fails to Outshine a Single Star"
Like a massive, dormant volcano, the Milky Way's central black hole appears to be a sleeping monster. Black holes are regions of spacetime where gravity is so strong that “what goes into them does not come out,” says Avery Broderick, a faculty member at the Perimeter Institute. As the name implies, black holes are intrinsically dark, with no light or matter able to escape once they have passed the threshold of no return known as the event horizon. But as black holes feast on the surrounding gas and stars, their accretion disks can shine and produce extraordinary energy. They can even outshine their host galaxies.