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HEAPOW: The Wow Burst (2013 May 06)

Just after 3:47 a.m. EDT on Saturday, April 27, the Gamma-ray Burst Monitor on the Fermi Gamma-ray Space Telescope detected the brightest Gamma-ray burst ever seen. The burst produced radiation at energies up to 94 giga-electron volts, about three times higher than the previous record. It also set the record as the longest GRB ever; the GeV emission from the burst lasted for hours, and it remained detectable by the LAT for the better part of a day. An accurate position by the Swift space observatory allowed detection of the burst by ground-based optical, infrared and radio telescopes, making this one of the best-studied GRBs. This GRB was probably produced by the catastrophic death of a massive star that suddenly ran out of nuclear fuel. When this happens, the core of the star collapses into a black hole. Models suggest that as the black hole at the center of the star accretes matter from the star, a powerful jet forms on either side of the black hole. These jets then rip through the star, blowing it apart. GRB 130427A was so bright because it was one of the nearest bursts ever seen, and astronomers are continuing observations, hoping to find the optical supernova associated with the Gamma-ray burst.

[i][b](Credit: NASA/DOE/Fermi LAT Collaboration)[/b][/i]

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[i][b](Credit: NASA/Swift/Stefan Immler)[/b][/i]

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A record-setting blast of gamma rays from a dying star in a distant galaxy has wowed astronomers around the world. The eruption, which is classified as a gamma-ray burst, or GRB, and designated GRB 130427A, produced the highest-energy light ever detected from such an event.

"We have waited a long time for a gamma-ray burst this shockingly, eye-wateringly bright," said Julie McEnery, project scientist for the Fermi Gamma-ray Space Telescope at NASA's Goddard Space Flight Center in Greenbelt, Md. "The GRB lasted so long that a record number of telescopes on the ground were able to catch it while space-based observations were still ongoing."

Just after 3:47 a.m. EDT on Saturday, April 27, Fermi's Gamma-ray Burst Monitor (GBM) triggered on an eruption of high-energy light in the constellation Leo. The burst occurred as NASA's Swift satellite was slewing between targets, which delayed its Burst Alert Telescope's detection by less than a minute.

Fermi's 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 LAT'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, based on the rapid accurate position from Swift. Astronomers quickly learned that the GRB was located about 3.6 billion light-years away, which for these events is relatively close.

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.

"This GRB is in the closest 5 percent of bursts, so the big push now is to find an emerging supernova, which accompanies nearly all long GRBs at this distance," said Goddard's Neil Gehrels, principal investigator for Swift.

Ground-based observatories are monitoring the location of GRB 130427A and expect to find an underlying supernova by midmonth.

Ann wrote:My friend Arne Lindengard has just sent me a mail telling me that GRB 130427A has just got a supernova name, too, SN 2013cq. According to Arne, the supernova briefly reached magnitude 12.

I must admit that I couldn't find the supernova when I googled it.

Ann

Ann wrote:I checked that page, but I couldn't find it! Where is it?

Ann

Web page last modified on 05/19/2013 13:02:22 .   For yesterday's updates, go to the updates page.

Created entries for 2 supernovae
Added images of 2013ch (Mag 15.2), 2013cr (Mag 17.0), CSS130513:142344+122507, CSS130513:151139+200912 (Mag 18.6), PSN J10445072+0636042
News: 2013cg in NGC 2891 is a bright Type Ia on the rise. >>