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STS-125: The mission

A detailed step-by-step preview of space shuttle Atlantis' STS-125 mission to extend the life and vision of the Hubble Space Telescope.

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STS-125: The EVAs

The lead spacewalk officer provides indepth explanations of the five EVAs to service Hubble during Atlantis' flight.

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STS-125: The crew

The seven shuttle Atlantis astronauts hold a press conference one month before their planned launch to Hubble.

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STS-125: NASA leaders

The leaders of NASA's Space Operations and Science directorates give their insights into the upcoming shuttle mission to the Hubble Space Telescope.

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STS-125: Shuttle boss

The head of NASA's space shuttle program discusses the risks and plans for Atlantis' trek to Hubble.

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The Hubble program

An overview of the Hubble Space Telescope program and the planning that has gone into the final servicing mission.

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Hubble's future science

The new instruments to be installed into Hubble and the future science objectives for the observatory are previewed.

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Atlantis on the pad

Shuttle Atlantis makes the slow journey from the Vehicle Assembly Building to launch pad 39A for the STS-125 mission to service Hubble.

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Meet the Hubble crew

Meet the crew launching on Atlantis' STS-125 mission to service the Hubble Space Telescope and learn how each became an astronaut in this special biography movie.

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Naked eye gamma-ray burst was aimed squarely at Earth
UNIVERSITY OF CALIFORNIA-BERKELEY NEWS RELEASE
Posted: September 10, 2008

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!"

Another paper, submitted weeks after Bloom's paper and largely confirming those results, appears in the Sept. 11 issue of Nature and is authored by graduate student Judith Racusin of Pennsylvania State University and her colleagues.

Authors of the ApJ paper also included Weidong Li, Nathaniel R. Butler, D. Kocevski, Ryan J. Foley, R. Chornock, D. L. Starr, B. Macomber and D. Poznanski of UC Berkeley; D. A. Kann and S. Klose of the Thuringer Landessternwarte Tautenburg in Germany; H.-W. Chen of the University of Chicago; J. X. Prochaska of the University of California Observatories/Lick Observatory, based at UC Santa Cruz; M. F. Skrutskie of the University of Virginia, Charlottesville; S. Lopez of the Universidad de Chile in Santiago, Chile; P. Hall of Toronto, Ontario, Canada; K. Glazebrook of the Centre for Astrophysics and Supercomputing at Swinburne University of Technology in Hawthorn, Australia; and C. H. Blake of the Harvard-Smithsonian Center for Astrophysics.