Tuesday, March 6, 2012

Supernova Countdown

About 165 years ago, Eta Carinae mysteriously became the second brightest star in the sky. In 20 years, after ejecting more mass than our sun, it unexpectedly faded. N. Smith / J.A. Morse (U. Colorado) et al. / NASA

Supernova Countdown: Giant Star Could Explode Any Day Now -- Time

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.

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