Is supernova a clue to early universe?

Dinosaurs were just beginning to thump across Earth when an enormous star exploded in a galaxy not too far away. Its light finally reached Robert Quimby's telescope last September in what researchers now call the brightest, most powerful supernova they have ever seen.

It also appears to be far different from any they have seen before. The team of researchers argues that they may have witnessed for the first time a stellar endgame similar to blasts that obliterated many of the universe's first stars more than 12.6 billion years ago.

These first stars - hundreds of times more massive and millions of times brighter than the sun - are thought to have lived briefly and exploded violently. They exploded so violently that, instead of collapsing upon themselves and creating neutron stars or black holes like most supernovae, these stars were annihilated. In the process, they jetted their star dust into the cosmos and seeded the young universe with a range of chemical elements forged in their furnaces. It's these elements that became the building blocks for new generations of stars, planets, and eventually, organic life.

The mystery is why Supernova 2006GY exploded at all, since conditions in the universe have changed so dramatically from that early period, according to the team of U.S. researchers, who made their case at a briefing in Washington Monday.

That's not the only mystery, other researchers say.

"We don't actually know the mechanism by which this star exploded," acknowledges Mario Livio, an astrophysicist with the Space Telescope Science Institute in Baltimore. But, he adds, data from the supernova seem to rule out other plausible explanations, leaving the early-star mechanism as the last hypothesis standing. This "tantalizing possibility ... makes this supernova even more intriguing," he says.

The supernova appears near the core of a spiral galaxy 240 million light-years away, in the constellation Perseus. Dr. Quimby discovered it with a telescopic munchkin: an 18-inch automated telescope and software he developed as a graduate student at the University of Texas in Austin. The scope runs by itself all night, looking at galaxy clusters for signs of stellar deaths. "When I get up in the morning, if I see a dot" in an image "where there wasn't one before, that's a supernova," he says.

Typically, he conducts his own follow-up studies. But at the time his telescope captured the explosion last year, he was in the midst of writing his PhD thesis. "I was actively trying not to find anything interesting to distract me," he recalls. When the image popped up, "I said, 'Yeah, it's a supernova. I'll just tell other people about it' " and let them do the follow-up work.