Suicidal gas cloud

Posted on February 13, 2012

Very Large TelescopeGenerally considered to be a “starving” black hole because it is not currently in the process of gobbling up the huge amounts of matter usually associated with these cosmic vaccum cleaners, it looks as though the dark giant at the centre of our own Milky Way is about to wake up with an appetite.

The central parts of the Milky Way, as observe...

Sagittarius A*

Off in the crowded distance of Sagittarius A**, where we find our very own supermassive black hole, an apparently sucidal cloud of gas is heading towards a distinctly terminal meeting with the black hole.

While our own black hole is normally placid and quiet that may be due to its current state of starvation from recent – in astronomical terms – meals. With the approach of a gas cloud, the gravity of the black hole will shred the cloud and in the process should generate enormous flares of radiation, waking up our greedy hole from its normally quiet state.

The suicidal cloud of gas was spotted thanks to Stefan Gillessen of the Max Planck Institute for Extraterrestrial Physics located in Garching, German. As is common in astronomy from Europe these days, the telescope used was both a long way from Germany and a long way up from sea level, in this case the Very Large Telescope Array in Chile. The cloud is no tiny bit of stuff either – it is about three times the mass of the Earth and is moving at nearly 2,500 kilometres per second towards its final demise in the heart of Sagittarius A* and our home-grown black hole.

Simulated view of a black hole in front of the...

More hyperactive black holes fuelled by inflowing gasses emit huge amounts of radiation and are known as quasars but stand in dramatic contrast to our own quiet one in Sagittarius A*. That could all change as soon as 2013 when, Gillessen’s team have calculated, is when the suicidal gas cloud will get dangerously close and start to be torn apart by gravitational stress. Most of the cloud will thereafter spiral down into the gravity well and emit vastly more light than has been the case in the past for our black hole.

Although not visible to the naked eye, mch to the disappointment of amateur astronomers, the adiation will give the professional stargazers clues why our black hole is normally so very different from the quasars we see all over the night sky. For amateur scientists though, the near future looks to bring a wonderfu opportunity to know a magnificent change is going on at the heart of our galaxy even if it is completely beyond our sight.