Echoes of Ancient Flares: The “Quiet Monster” of the Milky Way Revealed

Scientists studied the past activity of Sagittarius A*, the supermassive black hole in our galaxy, by analyzing light echoes from x-ray flares, indicating frequent past material consumption and a historically brighter state.

The supermassive black hole at the heart of our Milky Way Galaxy is a quiet monster. However, Sagittarius A* (or Sgr A* for short) is not totally dormant. Occasionally it gobbles down a blob of molecular gas or even a star and then suffers a bit of indigestion. That emits x-ray flares to surrounding space.