A giant new breed of supernova

May 8, 2007 06:39 GMT  ·  By
An artist's conception shows a stellar explosion on the scale seen in the supernova known as SN 2006gy.
   An artist's conception shows a stellar explosion on the scale seen in the supernova known as SN 2006gy.

Astronomers have just detected the brightest explosion of a star ever recorded, a huge new breed of supernova more than 100 times bigger than any one observed so far.

The violent blast was photographed by both terrestrial telescopes and NASA's orbiting Chandra X-Ray Observatory in a galaxy far from our own Milky Way.

The event was the explosion of a gigantic star, named SN 2006gy, 150 times more massive than our Sun, located in a galaxy 240 million light-years from Earth, called NGC 1260.

So, because of the impressive distance, it wasn't too obvious for astronomers, and it was just its sheer size that brought it to our attention.

The weird thing is that the giant star didn't follow the usual predictions for a star of its size. Instead of collapsing into a massive supernova, sucking all its mass into a gravitational sinkhole, or blowing away much of its mass to become a superdense neutron star, it just blasted in a tremendous thermonuclear explosion, that would make the simultaneous explosion of all the global nuclear arsenal look like a mere firecracker. "This is Einstein's famous equation E=mc2 put into practice," said Mario Livio, a senior astrophysicist at the Space Telescope Science Institute.

Some astronomers believe many of the universe's first generation of stars were as massive as this one. Thus, SN 2006gy could shed light on how the first stars lived and died.

This explosion made scientists think of another giant star in our own galaxy, called Eta Carinae, the most massive and energetic star observed in our own galaxy, and the fact that one day, it too could blow up much in the same way.

That would be an impressive picture, because "If Eta Carinae were to blow up like SN 2006gy, we'd definitely notice it", said David Pooley, the Berkeley astronomer who was in charge of Chandra's observations. "It would be so bright that you could see it during the day, and you could even read a book by its light at night."