Wednesday, 7 November 2012
Milky Way black hole shoots brightest ever flare
Posted by Scott Malthouse
One of the best parts of studying space is all the weird puzzles that it throws at scientists on a seemingly constant basis. Well now we have another one as vexed astronomers have observed the brightest X-ray flare ever emitted from the black hole in the centre of the Milky Way.
Once a day the black hole, known as Sagittarius A*, shoots out an x-ray flare that scientists measure using instruments like the Chandra X-Ray Observatory. But back in February, Chandra detected a flare unlike any other. It was 150 times brighter that the usual flares, leading experts to wonder what the hell was going on.
However, they may have an answer. The intense flare could have been the result of an asteroid or planet being 'swallowed up' by Sagittarius A* before spewing out the energy in the form of x-rays.
"Suddenly, for whatever reason, Sagittarius A* is eating a lot more," said Michael Nowak, a research scientist at MIT Kavli and co-author of a new paper in the Astrophysical Journal. "One theory is that every so often, an asteroid gets close to the black hole, the black hole stretches and rips it to pieces, and eats the material and turns it into radiation, so you see these big flares."
As black holes age they slow down, 'eating' planets and stars at a slower rate, therefore giving off a steadier pattern of flares, but Sagittarius A* doesn't seem to be slowing down.
Weirdly, the black hole should actually be a million times brighter than it is because of the amount of gas in its surroundings. But it looks like it's spewing out most of the matter it would actually consume, which shouldn't happen.