Hubble Pinpoints Record-Breaking Explosion
04.10.08
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Photo No.: STScI-PRC08-17
Credit: NASA; ESA; N. Tanvir (University of Leicester); A. Fruchter (STScI)
Peering across 7.5 billion light-years and halfway back to the Big Bang, NASA's
Hubble Space Telescope has photographed the fading optical counterpart of a
powerful gamma ray burst that holds the record for being the intrinsically
brightest naked-eye object ever seen from Earth. For nearly a minute this single
star was as bright as 10 million galaxies.
Hubble Wide Field and Planetary Camera 2 (WFPC2) 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 and other electromagnetic radiation at 2:12 a.m.
EDT on March 19, and was detected by Swift, NASA's gamma ray burst
watchdog satellite.
Immediately after the explosion, the gamma ray burst glowed as a dim 5th
magnitude "star" in the spring constellation Bootes. Designated GRB 080319B,
the intergalactic firework has been fading away ever since then.
Hubble astronomers had hoped to see the host galaxy where the burst
presumably originated, but were taken aback that the light from the GRB is still
drowning out the galaxy's light even three weeks after the explosion. This is
particularly surprising 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. The
slow fading leaves astronomers puzzling about just where the energy came from
to power this GRB, and makes Hubble's next observations of this object in May
all the more crucial.
Called a long-duration gamma ray burst, such events are theorized to be caused
by the death of a very massive star, perhaps weighing as much as 50 times our
Sun. 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 a blowtorch-like beam that, in this case,
was aimed directly at Earth.
The Hubble exposure also shows field galaxies around the fading optical
component of the gamma ray burst, which are probably unrelated to the burst
itself.
The Hubble Space Telescope is a project of international cooperation between
NASA and the European Space Agency and is managed by NASA's Goddard
Space Flight Center in Greenbelt, Md. The Space Telescope Science Institute
conducts Hubble science operations. The institute is operated for NASA by the
Association of Universities for Research in Astronomy, Inc., Washington, D.C.
View more information and images on the discovery at the following Web site:
> HubbleSite.org
For more information on this story, contact:
Ray Villard
Space Telescope Science Institute, Baltimore, Md.
410-338-4514
villard@stsci.edu
Nial Tanvir
University of Leicester
011-44-116-223-1217
nrt3@star.le.ac.uk
Andy Fruchter
Space Telescope Science Institute, Baltimore, Md.
410-338-5018
fruchter@stsci.edu