Hubble Pinpoints Visible Glow of Brightest Gamma Ray Burst (4/15/2008)

Gamma Ray Burst 080319B

Record breaking explosion continues to astound astronomers

University of Leicester astronomers have used NASA's Hubble Space Telescope to peer across 7.5 billions light-years, halfway back to the big bang, to photograph the fading optical counterpart of a powerful gamma-ray burst.

Hubble images taken on Monday April 7 show the fading optical counterpart of the titanic blast. The object erupted in a brilliant flash of gamma-rays, light and other radiation at 2:12 a.m. EDT on March 19, and was detected by the UK/US/Italian gamma-ray burst watchdog satellite, Swift, which carries a University of Leicester camera.

This particular burst astonished astronomers by breaking the record for being the intrinsically brightest naked-eye object ever seen from Earth. For nearly a minute, this single distant star was brighter than ten million galaxies.

Gamma-ray bursts are thought to be caused by the death of a very massive star. Such explosions, sometimes dubbed "hypernovae", are more powerful than ordinary supernova explosions, and are far more luminous, in part because their energy seems to be concentrated into blowtorch-like beam that, in this case, was aimed directly at Earth.

The researchers were taken aback by the new HST images because the fading ember of the burst is still so bright it drowns out any light from the galaxy in which it sits.

"This is particularly surprising precisely because it was such a bright GRB initially. Previously, bright bursts have tended to fade more rapidly, which fits in to the theory that brighter GRBs emit their energy in a more tightly confined beam", said Prof Nial Tanvir who led the Hubble campaign.

"The slow fading leaves astronomers puzzling about just where the energy came from to power this GRB, and makes HST's next observations of this object in May all the more crucial.", said Dr Andrew Levan of the University of Warwick, another team member.

Prof Tanvir will be giving a public lecture at the University on 27th May, explaining the mysterious phenomena of gamma-ray bursts, and giving an update on the latest results.

Note: This story has been adapted from a news release issued by the University of Leicester

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