Brightest stellar explosion heralds new type of long-distance astronomySeptember 11, 2008March 19 gamma-ray burst was first with optical component visible to naked eye Berkeley -- A flash of light that blinded even small telescopes six months ago was the brightest astronomical explosion ever observed - visible to the naked eye despite originating halfway across the universe. The gamma-ray burst, catalogued as GRB 080319B, was the result of a massive star's explosion 7.5 billion years ago that sent a pencil-beam of intense light on a direct collision course for Earth. It is the only known gamma-ray burst to have had a visible component bright enough to see with the naked eye.
"This was the brightest optical and infrared event that mankind has ever recorded," said Joshua Bloom, an assistant professor of astronomy at the University of California, Berkeley, and first author of an analysis of the event submitted to The Astrophysical Journal (ApJ) less than a week after the burst and accepted this week. "When more of these events are detected, we will open up the possibility of studying the infant universe with this new tool." The gamma-ray burst was first detected by NASA's Swift satellite on March 19, after which many Earth- and space-based telescopes slewed into position to observe the rapidly fading light. Situated within the constellation Bootes, its flash eventually was pinpointed at a distance of about 7.5 billion light years. Bloom's group, using a robotic telescope in Arizona, began observing the intense infrared light just 54 seconds after the event began. The telescope, called the Peters Automated Infrared Imaging Telescope (PAIRITEL), was operating autonomously on a direct link from the Swift satellite. Bloom's graduate students Daniel Perley and Adam A. Miller analyzed the data. "This was the most powerful event ever seen in human existence," enthused Bloom's coauthor Alex Filippenko, UC Berkeley professor of astronomy. "A star that blew up and could be seen - barely - with the naked eye on a dark, moonless night, even though seven and a half billion light years away, is just astonishing." Filippenko calculated that if the supernova were located about 6,000 light years from Earth, the gamma-ray burst would have appeared as bright as the sun. Perley noted, too, that the burst at its peak was about 200 million times brighter than the entire galaxy in which it occurred. Filippenko said that it is unlikely that anyone actually saw the flash, because it lasted only a few tens of seconds and appeared on a night with a bright moon. Astronomers know it reached a magnitude of 5.6, close to the limits of human vision, because a Polish observing program known as Pi of the Sky took several photos of the gamma-ray burst's afterglow at the Las Campanas Observatory in Chile. The Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory also followed the fading afterglow of the burst, as did the Gemini South telescope in Chile. Bloom and his colleagues combined these observations with Swift data and Pi of the Sky images to complete their analysis. The assimilation of new information about the event was particularly noteworthy. Less than six days after the event, Bloom's group submitted a 42-page paper written during a planned mountain retreat. Miller, then new to the fast-paced gamma-ray burst field said, "It was quite an introduction to research - my heart was racing for a week. I'm glad we decided to write instead of ski!" University of California - Berkeley | |||||||||||||||||||||
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Related Gamma-ray Current Events and Gamma-ray News Articles NASA's Swift Looks to Comets for a Cool View NASA's Swift Gamma-ray Explorer satellite rocketed into space in 2004 on a mission to study some of the highest-energy events in the universe. First gamma-ray-only pulsar observation opens new window on stellar evolution About three times a second, a 10,000-year-old stellar corpse sweeps a beam of gamma-rays toward Earth. NASA'S Fermi Telescope Discovers First Gamma-Ray-Only Pulsar About three times a second, a 10,000-year-old stellar corpse sweeps a beam of gamma-rays toward Earth. Discovered by NASA's Fermi Gamma-ray Space Telescope, the object, called a pulsar, is the first one known that only "blinks" in gamma rays. NASA's Swift Catches Farthest Ever Gamma-Ray Burst NASA's Swift satellite has found the most distant gamma-ray burst ever detected. The blast, designated GRB 080913, arose from an exploding star 12.8 billion light-years away. Radioactivity: Discover the lowest amounts with new methods Detecting ever lower amounts of ionising radiation with ever better methods - sci-entists have had this goal since the start of the nuclear age. 'Naked-eye' gamma-ray burst was aimed squarely at Earth Data from satellites and observatories around the globe show a jet from a powerful stellar explosion witnessed March 19 was aimed almost directly at Earth. The Double Firing Burst Astronomers from around the world combined data from ground- and space-based telescopes to paint a detailed portrait of the brightest explosion ever seen. The observations reveal that the jets of the gamma-ray burst called GRB 080319B were aimed almost directly at the Earth. U.S. Air Force Technology Helps Scientists Understand Plant Root Function The McClellan Nuclear Radiation Center (MNRC) in Sacramento, CA was developed by the U.S. Air Force to detect corrosion and defects in aircraft structure using an imaging technique called neutron radiography. This technique is currently helping soil scientists understand the function of plant roots and their uptake of water and nutrients. GLAST Observatory renamed for Fermi, reveals entire gamma-ray sky The U.S. Department of Energy (DOE) and NASA announced today that the Gamma-Ray Large Area Space Telescope (GLAST) has revealed its first all-sky map in gamma rays. Study shows clumps and streams of dark matter in inner regions of the Milky Way Using one of the most powerful supercomputers in the world to simulate the halo of dark matter that envelopes our galaxy, researchers found dense clumps and streams of the mysterious stuff lurking in the inner regions of the halo, in the same neighborhood as our solar system. More Gamma-ray Current Events and Gamma-ray News Articles |
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