The largest X-ray flare ever detected from the monster black hole at the center of our galaxy was observed by NASA's Chandra X-ray Observatory, according to NASA.
The black hole, called Sagittarius A*, or Sgr A*, contained about 4.5 million times the mass of our sun.
"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."
An X-ray flare was detected from Sgr A* on Sept. 14, 2013 by Haggard and her team. The flare was 400 times brighter than its usual dim output. (The "megaflare," according to NASA, was three times brighter than the last flare in 2012). Then again, on Oct. 20, 2014, Chandra noted another giant X-ray flare 200 times brighter than the norm.
G2 was closest to the black hole in the spring of 2014, astronomers estimated, and the September 2013 flare was around 100 times closer than G2, so the flare was most likely not related to the gas cloud.
So what caused the show? One thought is that an asteroid flirted too closely to Sgr A* and was torn apart by the black hole's gravity. "If an asteroid was torn apart, it would go around the black hole for a couple of hours - like water circling an open drain - before falling in," said co-author Fred Baganoff of the Massachusetts Institute of Technology in Cambridge, Mass. "That's just how long we saw the brightest X-ray flare last, so that is an intriguing clue for us to consider."
The second theory relates to the dynamics of solar flares: the magnetic fields loop, get tangled and snap. The snapping could cause an outburst of energy.
"The bottom line is the jury is still out on what's causing these giant flares from Sgr A*," said co-author Gabriele Ponti of the Max Planck Institute for Astrophysics in Garching, Germany. "Such rare and extreme events give us a unique chance to use a mere trickle of infalling matter to understand the physics of one of the most bizarre objects in our galaxy."
In addition to watching x-ray flare, the G2 campaign has been keeping an eye on a magnetar: a neutron star with a strong magnetic field, which is in close proximity to Sgr A*. This magnetar is undergoing a long X-ray outburst and Chandra is helping researchers decipher it.
