Hungry Rumblings from the Black Hole at the Center of the Milky Way

There is a monster at the center of our galaxy: A black hole, known as Sagittarius A*, weighing 4.3 million times as the sun and measuring about 25 million kilometers (15 million miles) across. At present the monster is slumbering, betraying its presence only by a slight snore of radiation, but it was not always so calm. A new study using the Chandra X-ray Observatory has picked up echoes of past outbursts within the past few hundred years--moments when Sagittarius A* was wide awake, blazing a million times as brightly as it does today.