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Compton Gamma Ray Observatory equipment helps to sniff out radioactive sources. Remnants of the Compton Gamma Ray Observatory (pictured), are being used in other fields.NASA The 9-year mission of NASA’s Compton Gamma Ray Observatory ended in 2000 with a plunge into the Pacific Ocean. But its spare parts are living on — as a detector of dirty bombs. James Ryan, an astrophysicist at the University of New Hampshire in Durham, has recycled parts from one of the space telescope’s old instruments, realizing that they can work just as well pointing horizontally as they did vertically up into the heavens. The...

Earth could be in for a neighborhood dispute with a death star, according to an Australian astronomer. A spectacular rotating pinwheel system just down the astronomical road from Earth — 8,000 light years away — includes an unstable Wolf-Rayet star that could explode. Eight years ago, WR104 was discovered in the constellation Sagittarius by Sydney University astronomer Peter Tuthill. A Wolf-Rayet star is the last step on the way to a supernova — the explosion of a star at the end of its life. Images from the Mauna Kea in Hawaii telescope show that every eight months the two stars...

GREENBELT, Md. - A new NASA space telescope will give scientists a peek at some of the most energetic objects and events in the universe. The new Gamma-ray Large Area Space Telescope to be launched next spring doesn't see visible light like our eyes, but gamma rays, the most energetic photons in the electromagnetic spectrum. They are produced by black holes, supernovae, neutron stars and other phenomena. GLAST will be the first gamma ray observatory to survey the entire sky. Scientists are hoping it will provide clues about dark matter, the early universe and allow them to test fundamental principles...

LONDON (Reuters) - Teams of international scientists have used observations from NASA's Swift satellite and other telescopes to witness the evolution of a cosmic blast into a stellar explosion or supernova. The blast is thought to be a milder type of gamma-ray burst (GRB) -- the most powerful type of explosion known to astronomers -- called an X-ray flash. It is known as GRB060218 after the February 18 date it began in the constellation of Aries about 440 million light years away. A light year is about 6 trillion miles, the distance light travels in a year. "This extends the...

Gamma-ray bursts could be the signature of ultradense stars. This X-ray image shows the 3C58 pulsar, the remnant of a supernova noted on Earth in AD 1181, which astronomers suspect may be a quark star. It lies about 10,000 light years from Earth.© NASA/SAO/CXC/P.Slane et al. Intense flashes of gamma rays in far-off galaxies might be produced by a bizarre kind of star, consisting of phenomenally dense material in which the particles that make up atomic nuclei have fallen apart. Two astrophysicists have proposed that gamma-ray (gamma-ray) bursts, whose origins have foxed astronomers for decades, might be the signatures of...

After a Trio of Explosions Scientists say Supernova is ImminentThree powerful recent blasts from three wholly different regions in space have left scientists scrambling. The blasts, which lasted only a few seconds, might be early alert systems for star explosions called supernovae, which could start appearing any day. The first two blasts, called X-ray flashes, occurred on September 12 and 16. These were followed by a more powerful burst on September 24. The burst seems to be on the cusp between an X-ray flash and a full-fledged gamma ray burst, a discovery interesting in its own right. If these signals...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2004 January 30 X-Ray Rings Expand from a Gamma Ray Burst Credit: S. Vaughan, R. Willingale (U. Leicester) et al., XMM, ESA Explanation: Why do x-ray rings appear to emanate from a gamma-ray burst? The surprising answer has little to do with the explosion itself but rather with light reflected off sheets of dust-laden gas in our own Milky Way Galaxy. GRB 031203 was a tremendous explosion --...

A DEVASTATING burst of gamma-rays may have caused one of Earth's worst mass extinctions, 443 million years ago. A team of astrophysicists and palaeontologists says the pattern of trilobite extinctions at that time resembles the expected effects of a nearby gamma-ray burst (GRB). Although other experts have greeted the idea with some scepticism, most agree that it deserves further investigation. GRBs are the most powerful explosions known. As giant stars collapse into black holes at the end of their lives, they fire incredibly intense pulses of gamma rays from their poles that can be detected even from across the universe...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2003 April 14 A Gamma Ray Burst - Supernova Connection Credit: Al Kelly (JSCAS/NASA) & Arne Henden (Flagstaff/USNO) Explanation: New evidence has emerged that a mysterious type of explosion known as a gamma ray burst is indeed connected to a supernova of the type visible in the above image. Two weeks ago, the orbiting HETE satellite detected gamma-ray burst GRB030329. The extremely bright burst was found hours later...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2003 March 25 A Slow Explosion Credit: Y. Grosdidier (U. Montreal) et al., WFPC2, HST, NASA Explanation: Why would a gamma ray burst fade so slowly? This behavior, recorded last October, is considered a new clue into the cause of gamma-ray bursts, the most powerful explosions known in the universe. The burst, first detected by the orbiting HETE satellite and later tracked by numerous ground-based telescopes, showed an...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 December 19 RAPTOR Images GRB 021211Credit: P. Wozniak, W.T. Vestrand, et al., RAPTOR Project, LANL Explanation: On December 11 astronomers found one of the brightest and most distant explosions in the Universe - a gamma-ray burst - hiding in the glare of a relatively nearby star. The earliest image of the burst's visible light was caught by an earthbound RAPTOR (RAPid Telescopes for Optical Response). The two...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 September 6 HESS Gamma-Ray TelescopeCredit: The HESS Collaboration Explanation: Most ground-based telescopes with lenses and mirrors are hindered by the Earth's nurturing, protective atmosphere that blurs images and scatters and absorbs light. But this telescope was designed to detect extreme gamma rays - photons with over 100 billion times the energy of visible light - and actually requires the atmosphere to operate. As the gamma rays impact...