2003 SPACE SCIENCE VIDEOTAPES |
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Tape Title | Record ID | Date Produced | TRT: |
Synopsis |
| SCIENTISTS FIND "ROSETTA STONE" TO DECODE GAMMA-RAY BURST MYSTERY | G03-042 | 06/19/03 | 00:06:58 | Scientists have pieced together the key elements of a gamma ray burst, from star death to dramatic black hole birth, thanks to what they are calling a Rosetta Stone of such bursts observed on March 29, 2003.
This telling March 29 burst in the constellation Leo, one of the brightest and closest on record, reveals for the first time that a gamma-ray burst and a supernova -- the two most energetic explosions known in the Universe -- occur nearly simultaneously, a quick and powerful one-two punch. The burst was detected by NASA's High-Energy Transient Explorer (HETE) and observed in detail with the European Southern Observatory's Very Large Telescope (VLT) at the Paranal Observatory in Chile.
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TAPE CONTENTS: |
| ITEM (1): A Star's Collapse and Gamma Ray Burst - Thousands of years prior to this explosion, a very massive star, running out of fuel, let loose much of its outer envelope, transforming itself into a bluish Wolf-Rayet star. The Wolf-Rayet star -- containing about 10 solar masses worth of helium, oxygen and heavier elements -- rapidly depleted its fuel, triggering the Type Ic supernova / gamma-ray burst event. The core collapsed, without the star's outer part knowing. A black hole formed inside surrounded by a disk of accreting matter, and, within a few seconds, launched a jet of matter away from the black hole that ultimately made the gamma-ray burst. The surface layers of the star blast outward, forming the colorful patterns typical of supernova remnants.
Courtesy: NASA
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| ITEM (2): Theoretical Model of The Creation of a Gamma Ray Burst - This "collapsar" model, introduced by Woosley in 1993, best explains the observation of GRB 030329, as opposed to the "supranova" and "merging neutron star" models.
As the core collapses, a jet of newly forged radioactive nickel-56 passes through the inner star toward the outer shell of the star and, in conjunction with vigorous winds blowing off the disk inside, shatters the star. This shattering represents the supernova event. Meanwhile, collisions among pieces of the jet moving at different velocities, all very close to light speed, created the gamma-ray burst.
Courtesy: NASA
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| ITEM (3): HETE Spacecraft Animation - HETE was built by MIT as a mission of opportunity under the NASA Explorer Program, with collaboration among U.S. universities, Los Alamos National Laboratory, and scientists and organizations in Brazil, France, India, Italy and Japan.
Courtesy: NASA/MIT
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| ITEM (4): A Chance Observation - The Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI) satellite was snapping pictures of solar flares on December 6, 2002, when it caught an extremely bright gamma-ray burst in the background, over the edge of the Sun, revealing for the first time that the gamma-rays in such a burst are polarized. The result indicates intense magnetic fields may be the driving force behind these awesome explosions.
Courtesy: NASA
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| ITEM (5): Gamma-Ray Burst - Death Cry of an Exploding Star - Gamma-ray bursts are remopte flashes of gamma-ray light that pop off about once a day randomly in the sky, briefly shining as bright as a million trillion suns.
Courtesy: NASA
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