Friday, May 8, 1998
Blast brighter than a billion suns biggest thing since the Big Bang
"It could be completely new physics" ... Dr Bruce Grossan.
By RICHARD MACEY
An international team of astronomers has observed the biggest explosion ever recorded - a cataclysmic blast called by NASA the "most powerful explosion since the creation of the universe in the Big Bang". It happened inside a galaxy about 12 billion light years away, possibly just two billion years after time began.
The blast produced almost unimaginable amounts of energy called gamma rays which reached Earth at 10.34am on Monday, December 15, Sydney time.
Although our atmosphere shields us from such radiation, the rays were detected by an Italian/Dutch satellite, BeppoSAX, which directed the Hubble Space Telescope towards the blast.
The explosion, known as a gamma ray burst, was confirmed by NASA's orbiting Compton Observatory.
Releasing the news yesterday, NASA said the 50-second burst was hundreds of times larger than any exploding star and "about equal to the amount of energy radiated by our entire galaxy over a period of a couple of centuries". Our galaxy has up to 200 billion stars.
"Finding such a large energy release over such a brief period of time is unprecedented in astronomy, except for the Big Bang itself," NASA said.
Professor George Djorgovski, of the California Institute of Technology, added: "For about two seconds this burst was as luminous as all the rest of the entire universe".
The gamma ray bursts were first discovered in 1967, and one happens somewhere in the universe every day. They were originally mistaken by US spy satellites for secret nuclear tests.
A leading gamma ray burst hunter, Dr Bruce Grossan, of the University of California, conceded in Sydney that scientists could only speculate about their cause.
Some believed they were collisions between neutron stars - the corpses of stars that have collapsed to create objects just a few kilometres across but so densely packed that a spoonful weighs as much as a mountain.
Others argued that they were caused by neutron stars being sucked into black holes, which are in fact objects so massive that not even light can escape their gravity.
"I have a completely open mind," Dr Grossan said. "There may be exciting new objects out there we have never understood before and have never observed before. It could potentially be completely new physics."
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