Friday, February 17, 2012

Supernova Blast: Giant Star Eta Carinae to Explode Any Day

When the sun finally dies some 5 billion years from now, the end will come quietly, the conclusion of a long, uneventful life. Our star will, in a sense, go flabby, swelling first, releasing its outer layers into space and finally shrinking into the stellar corpse known as a white dwarf.

Things will play out quite differently for a supermassive star like Eta Carinae, which lies 7,500 light-years from Earth. Weighing at least a hundred times as much as our sun, it will go out more like an adolescent suicide bomber, blazing through its nuclear fuel in a mere couple of million years and exploding as a supernova, a blast so violent that its flash will briefly outshine the entire Milky Way. The corpse this kind of cosmic detonation leaves behind is a black hole.

For Eta Carinae, that violent end might not be long in coming, according to a report in the latest Nature. "We know it's close to the end of its life," says astronomer Armin Rest of the Space Telescope Science Institute and the lead author of the paper. "It could explode in a thousand years, or it could happen tomorrow." In astronomical terms, a thousand years might as well be tomorrow; as for a supernova blowing up literally tomorrow, well, that's almost unheard of.,8599,2106904,00.html?xid=gonewsedit