A ‘shockingly bright’ gamma-ray burst
May 7, 2013
A record-setting blast of gamma rays from a dying star in a galaxy about 3.6 billion light-years away has wowed astronomers around the world — the highest-energy light ever detected from such an event.
At 3:47 a.m. EDT, April 27, Fermi’s Gamma-ray Burst Monitor (GBM) triggered on an eruption, designated GRB 130427A, of high-energy light in the constellation Leo.
The Fermi Large Area Telescope (LAT) recorded one gamma ray with an energy of at least 94 billion electron volts (GeV), or some 35 billion times the energy of visible light, and about three times greater than the telescope’s previous record.
The GeV emission from the burst lasted for hours, and it remained detectable by the LAT for the better part of a day, setting a new record for the longest gamma-ray emission from a GRB.
The burst subsequently was detected in optical, infrared and radio wavelengths by ground-based observatories.
Gamma-ray bursts are the universe’s most luminous explosions. Astronomers think most occur when massive stars run out of nuclear fuel and collapse under their own weight. As the core collapses into a black hole, jets of material shoot outward at nearly the speed of light.
The jets bore all the way through the collapsing star and continue into space, where they interact with gas previously shed by the star and generate bright afterglows that fade with time.
If the GRB is near enough, astronomers usually discover a supernova at the site a week or so after the outburst.
Ground-based observatories are monitoring the location of GRB 130427A and expect to find an underlying supernova by midmonth.
Download additional graphics from NASA Goddard’s Scientific Visualization Studio
Archive of GRB notices from the Gamma-ray Coordination Network
“NASA’s Fermi Telescope Sees Most Extreme Gamma-ray Blast Yet” (02.19.09)
NASA’s Fermi Gamma-ray Space Telescope
NASA’s Swift mission