NASA | MSFC | SAO | CXC | 2015 Jan 05
The supermassive black hole at the center of our galaxy, called Sagittarius A*, or Sgr A*, is estimated to contain about 4.5 million times the mass of our sun.
Astronomers made the unexpected discovery while using Chandra to observe how Sgr A* would react to a nearby cloud of gas known as G2.
“Unfortunately, the G2 gas cloud didn't produce the fireworks we were hoping for when it got close to Sgr A*,” said lead researcher Daryl Haggard of Amherst College in Massachusetts. “However, nature often surprises us and we saw something else that was really exciting.”
On Sept. 14, 2013, Haggard and her team detected an X-ray flare from Sgr A* 400 times brighter than its usual, quiet state. This “megaflare” was nearly three times brighter than the previous brightest X-ray flare from Sgr A* in early 2012. After Sgr A* settled down, Chandra observed another enormous X-ray flare 200 times brighter than usual on Oct. 20, 2014. ...
Amherst Astronomy Professor Detects Record-Breaking Black Hole Outburst
Amherst College | 2015 Jan 05