Astronomers Watch Most Massive Star Ever Go Supernova
Rare behemoth star produces antimatter and collapses in a runaway nuclear reaction that leaves nothing behind Stars don't tend to go quietly, and the most massive of them all create a supernova explosion 50 to 100 times brighter than normal. Now astronomers have confirmed the existence of rare but huge stars that contain 200 times the mass of our sun, after spotting one unusually bright cosmic explosion in 2007. The supernova, called SN2007bi, remained visible almost two years after its first discovery -- a very unusual bonus for astronomers. A team has since analyzed the star's signature and published their findings in the Dec. 3 issue of the journal Nature. Turns out that the huge explosion represents a pair-instability supernova, in which a star has mostly run out of hydrogen and helium and only has a core of oxygen. Smaller stars consume that core until only iron remains, and then collapse into a...