APOD
Astronomy Picture of the Day
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Galactic Center Flicker Indicates Black Hole
Explanation: Why would the center of our Galaxy flicker? Many astronomers believe the only credible answer involves a black hole . During observations of Sagittarius A* with the orbiting Chandra X-ray Observatory , the bright X-ray source at the very center of our Milky Way brightened dramatically for a few minutes. Sagittarius A* is visible as the bright dot near the center of the above image . Since large objects cannot vary quickly, a small source is implicated in the variation. Evidence including the motions of central stars indicates that the center of our Galaxy is a massive place, however, estimated to be over a million times the mass of our Sun . Only one known type of object can fit so much mass in so small a volume: a black hole . This short flicker therefore provides additional evidence that a black hole does indeed reside at our Galaxy's center . If true, the flicker might have been caused by an object disrupting as it fell toward the disruptive monster .
| Date | September 10, 2001 |
|---|---|
| Credit | Credit: F. Baganoff ( MIT ) et al., CXO , NASA |
| Authors & editors: | Robert Nemiroff (MTU) & Jerry Bonnell (UMCP) |
| A service of: |
ASD at NASA / GSFC, NASA Science Activation & Michigan Tech. U. |



