NASA's Swift launch rescheduled for Saturday 11/20 , ~~12:10 - 1:10 p.m. EST

AP on Yahoo ^ | 11/17/04 | NASA

[NormsRevenge]

CAPE CANAVERAL, Fla. - With just hours left in the countdown, NASA (news - web sites) called off the launch Wednesday of a spacecraft that will hunt for emerging black holes.

The launch was postponed for at least a day because of trouble with an electronic box aboard the unmanned Delta rocket, part of the safety system for destroying the vehicle if it flies off course.

Once in orbit, NASA's Swift spacecraft will swivel quickly to detect gamma ray bursts in the universe, which scientists believe represent the creation of black holes. Black holes are believed to be the invisible remains of collapsed stars; black holes' gravitational pull is so great that not even light can escape from one.

Besides NASA, the Italian Space Agency and Britain's particle physics and astronomy research council are taking part in the $250 million mission.

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On the Net:

NASA: http://www.nasa.gov/mission_pages/swift/main/index.html

[NormsRevenge]

Swift's three instruments work together to glean as much information about each burst as possible. Swift's multiwavelength observations of GRBs and afterglow are completely simultaneous. The X-ray Telescope (XRT) and Ultraviolet/Optical Telescope (UVOT) have co-aligned fields-of-view, both within the Burst Alert Telescope (BAT) field-of-view, so that any source can be observed in all three wavebands.

When a GRB occurs, the BAT will be the first of Swift's instruments to detect it. Within about 10 seconds of the burst trigger, the BAT produces a burst localization, which is transmitted to ground observers. In addition, the BAT's position is fed to the Swift spacecraft so a slew can be performed, bringing the GRB into the XRT and UVOT's fields-of-view.

Within a minute after a burst, the XRT refines the BAT position. The UVOT produces an even-more accurate localization after about 200 seconds. Meanwhile, the BAT obtains a picture of how the gamma-ray emission evolves over time. X-ray spectra are available after about 20 minutes, and the UVOT filters complete their cycles after about 2 hours. Together, these observations provide a clear picture of the GRB and its afterglow over time in three distinct wavebands.

While not engaged in observations of a new GRB, Swift's telescopes perform preprogrammed observations, which include long-term follow-up of GRBs as well as other science.

Swift and Other Telescopes

Past and current advances in the understanding of gamma-ray bursts (GRBs) have come from the cooperation of many telescopes observing different wavebands. While Swift has the capability of making multiwavelength observations of GRBs, continued multiwavelength observations of GRBs by other telescopes is not only anticipated but is invaluable.

Swift facilitates community-wide contributions to GRB science in two ways. First, Swift disseminates GRB positions as soon as they are available. This allows operators of other satellite and ground-based telescopes to schedule immediate observations when feasible. Second, if a GRB is discovered by another telescope, the coordinates can be uploaded to Swift so that it can perform rapid observations of these bursts.

The Burst Alert Telescope (BAT) instrument, an integral component of the Swift spacecraft was assembled, tested and built at NASA Goddard Space Flight Center. + BAT instrument description

Image: Swift's three scientific instruments work together to learn as much as possible about gamma-ray bursts. Credit: NASA/GSFC

[SquirrelKing]

Comment #2 Removed by Moderator

What could you say on a thread like this to get blackballed by the mods?

Good post Norm, BTW.

[NormsRevenge]

T'was Not me, someone else made a comment about letting the spacecraft sit and save the money and not lay the cost on the grandkids when this very same day, the national debt ceiling was raised by 800 billio dollars.

I didn't ask to have it deleted or make a comment in response.

[SquirrelKing]

T'was Not me, someone else made a comment about letting the spacecraft sit and save the money and not lay the cost on the grandkids when this very same day, the national debt ceiling was raised by 800 billio dollars.

Geez. What a grump-a-lump.

Carry on.

[NormsRevenge]

NEW Info on the Swift launch

Pretty cool Virtual Launch Control Center

http://www.ksc.nasa.gov/elvnew/swift/vlcc.htm


Launch Date: November 20, 2004
Launch Time: 12:10 - 1:10 p.m. EST
Location: Cape Canaveral Air Force Station, Florida
Live Coverage: 10:30 a.m. EST

[NormsRevenge]

NASA Fact

Swift's three telescopes span the gamma-ray, X-ray, ultraviolet and optical light bands. A swath of the spectrum over a million times wider than what the Hubble Space Telescope detects.

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A composite Chandra X-ray (blue) and Palomar infrared (red and green) image of the supernova remnant W49B. Credit: X-ray: NASA/Chandra X-ray Center/Spitzer Science Center; Infrared: Caltech/Palomar

New Evidence Points to a Gamma-Ray Burst... In Our Own Backyard

Astronomers have uncovered evidence that a powerful gamma-ray burst, one of nature's most catastrophic explosions, occurred in our own Milky Way galaxy just a few thousand years ago.

Only 35,000 light years away lies W49B, the supernova remnant left over from the cataclysmic burst. New evidence pointing to a gamma ray burst origin for this remnant was discovered by X-ray data from the Chandra X-ray Observatory, combined with infrared observations from the Palomar 200-inch telescope in southern California.

The discovery is exciting for two reasons. It may be the first time a supernova remnant from a gamma-ray burst has been found so close to Earth. It also appears to be tied to a special type of black hole called a "collapsar," which was first theorized by scientists more than a decade ago.

"The nearest known gamma-ray burst to Earth is several million light years away -- most are billions of light years distant -- so the detection of the remnant of one in our own galaxy would be a major breakthrough," said William Reach of the California Institute of Technology.

W49B is barrel-shaped and ringed by bright, infrared "hoops." But one of its most intriguing features is the intense X-radiation produced by concentrations of iron and nickel ions along the axis of the barrel. This makes it "a prime candidate for being the remnant of a gamma-ray burst involving a black hole collapsar," according to Jonathan Keohane of NASA's Jet Propulsion Laboratory in Pasadena, Calif.

In a traditional supernova, only the outer parts of the star are flung outward during the explosion. But in the collapsar model, iron and nickel from the center of the exploding star is ejected outward along the jets of hot gas. W49B appears to fit the collapsar pattern.

For more than a decade, astronomers have suspected that gamma-ray bursts are produced when the core of a massive star collapses, forming a black hole collapsar. A disk of superhot, magnetized gas spins rapidly around the black hole, which pulls in most of the gas. But some is hurled outward in opposite directions at nearly the speed of light. An observer in the path of one of these jets would be blinded by a gamma-ray burst packing as much power as ten quadrillion suns.

Until the discovery of W49B, there was a problem with the collapsar theory. Massive stars -- stars large enough to form collapsars -- are usually formed in a dense cloud of dust. But the afterglow of gamma-ray bursts seem to point to the explosion taking place in a low-density gas.

Keohane and his colleagues believe barrel-shaped W49B nebula may help solve that problem.

The infrared image reveals four rings of warm gas that were most likely flung away from the star a few hundred thousand years before the explosion. A hot wind blowing from the star pushed these rings even further outward. By the time of its collapse, the star had carved out a low-density cavity immediately around itself.

"This star appears to have exploded inside a bubble it had created," Keohane of said. "In a sense, it dug its own grave."