History Of Sagittarius A AKA The Black Hole

Sagittarius A* believed to be a black hole at the center of our Milky Way galaxy, became subject of recent study.  "'The Awakening' --When Will the Supermassive Engine at the Heart of Our Galaxy Reignite?" - title of recent The Daily Galaxy article, where astronomers wonder why galactic core seems relatively quiet?   A team of astronomers used X-Ray satellites from Japan, the United States and Europeans Union to partially determine history of the black hole.  The picture (left) is an image of the black hole, captured by the Chandra X-Ray Observatory.  Perhaps, most interesting, the method used by team to discover something about the black hole's history:

"It turns out that, approximately 300 years ago, Sagittarius A* let loose, expelling a massive energy flare. Data taken from 1994 to 2005 revealed that clouds of gas near the central black hole, known as Sagittarius B2, brightened and faded quickly in X-ray light. The X-rays were emanating from just outside the black hole, created by the buildup of matter piling up outside the black hole, which subsequently heats up and expels X-rays. These pulses of X-ray take 300 years to traverse the distance between Sagittarius A* and Sagittarius B2, so that when we witness something happening in the cloud, it is responding to something that happened 300 years ago. Amazingly for us, in a rare occurrence of perfect cosmic timing, a region in Sagittarius B2, only 10 light-years across varied dramatically in brightness. "By observing how this cloud lit up and faded over 10 years, we could trace back the black hole’s activity 300 years ago," said Katsuji Koyama of Kyoto University. 'The black hole was a million times brighter three centuries ago. It must have unleashed an incredibly powerful flare.'"

Sgr A* Shoots Brightest Flare Ever!

Sagittarius A* (Sgr A*) is believed to be a supermassive black hole at the center of the Milky Way.  A recent Universe Today article reports the Chandra X-Ray Oberservatory recorded largest flare ever from Sgr A*.  "For some unknown reason, the black hole at the center of the Milky Way galaxy shoots out an X-ray flare about once a day. These flares last a few hours with the brightness ranging from a few times to nearly one hundred times that of the black hole’s regular output. But back in February 2012, astronomers using the Chandra X-Ray Observatory detected the brightest flare ever observed from the central black hole, also known as Sagittarius A*. The flare, recorded 26,000 light years away, was 150 times brighter than the black hole’s normal luminosity," reports article.  It is generally believed wandering asteroids or planets get too close and are drawn into the black hole.   The black hole vaporizes the solid body and x-rays emitted in the process. The energy burst is called a flare.  Is it the only possible explanation for increased activity at the center of our galaxy?