US space agency NASA announced that astronomers have witnessed the brightest ever explosion of one of the biggest ever stars. The stellar explosion may be a long-sought new type of supernova, according to observations by NASA's Chandra X-ray Observatory.

"This was a truly monstrous explosion, a hundred times more energetic than a typical supernova," said Nathan Smith of the University of California at Berkeley, who led a team of astronomers from California and the University of Texas in Austin. "That means the star that exploded might have been as massive as a star can get, about 150 times that of our sun. We've never seen that before."

"Of all exploding stars ever observed, this was the king," said Alex Filippenko, who led an observation team at Lick Observatory in California. "We were astonished to see how bright it got, and how long it lasted."

The star that produced SN 2006gy apparently expelled a large amount of mass prior to exploding. This large mass loss is similar to that seen from Eta Carinae, a massive star in our galaxy, raising suspicion that Eta Carinae may be poised to explode as a supernova. Although SN 2006gy is intrinsically the brightest supernova ever, it is in the galaxy NGC 1260, some 240 million light years away. However, Eta Carinae is only about 7,500 light years away in our own Milky Way galaxy.

Eta Carinae's explosion could be the best star-show in the history of modern civilization," according to Mario Livio of the Space Telescope Science Institute in Baltimore, Maryland. "We don't know for sure if Eta Carinae will explode soon, but we had better keep a close eye on it just in case."