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Latest Gamma-ray burst progenitors Stories

7e97418865e0e96b786f82f54bb4f35e1
2008-10-22 06:30:00

There's a universal tendency to heed Dylan Thomas's exhortation and go out with a bang instead of a whimper. Nowhere is this more evident than deep in the cosmos. When their time is up, stars make their exits in a number of flamboyant ways. The most massive stars leave with the greatest fanfare of all "“ blasting out gamma-ray bursts (GRBs), tremendous explosions that rock the Universe like nothing else. These spectacular blasts, second in power only to the Big Bang, occur when stars...

5b6e438b03e28054300103c0766878001
2008-10-21 10:54:04

For decades it was baffling. Out of the still night sky, astronomers peering through their telescopes would occasionally glimpse quick bursts of high-energy light popping off like flashbulbs at the far side of the universe. These bursts seemed impossibly powerful: to appear so bright from so very far away, they must vastly outshine entire galaxies containing hundreds of billions of stars. These explosions, called gamma ray bursts (GRBs), are by far the brightest and most energetic phenomena...

2f5fa3b67b6b70d6e3b46288d71e71131
2008-10-13 08:55:00

Gamma-ray bursts, powerful glares of high-energy that wash through the Universe once every day or so are, for a brief time, the brightest objects in the gamma-ray sky. ESA's Integral gamma-ray observatory has observed several low-luminosity gamma-ray bursts, confirming the existence of an entire population of weaker bursts hardly noticed so far. When it comes to detecting gamma-ray bursts (or GRBs), Integral is equipped with the most sensitive detector ever launched into space "“ the...

2008-06-29 06:00:57

By Luntz, Stephen A beautiful star system may eventually be a threat to Earth, although its discoverer stresses that the risk is small. Wolf-Rayet stars are considered the time bombs of the galaxy, likely to explode as supernovae in astronomically short timescales. They are enormous - generally tens of solar masses - and shedding material 100 billion times as fast as the Sun. Being close to a supernova is a health hazard for a living planet, but from a few hundred light-years away all one...

41cc43dd03d3db19a6a4c70ec982abd91
2007-10-17 14:55:00

With eyes that peer into the most energetic phenomena in the universe, ESA's Integral has been setting records, discovering the unexpected and helping understanding the unknown over its first five years. Integral was launched on 17 October 2002. Since then, the satellite has helped scientists make great strides in understanding the gamma-ray universe - from the atoms that make up all matter, giant black holes, mysterious gamma-ray bursts to the densest objects in the universe.  The...

ecd51814879567c75f5ce8495f7fb4f91
2007-06-12 11:50:31

Robotic Telescope Measures Speed of Material Ejected in Cosmic Death Using a robotic telescope at the ESO La Silla Observatory, astronomers have for the first time measured the velocity of the explosions known as gamma-ray bursts. The material is travelling at the extraordinary speed of more than 99.999% of the velocity of light, the maximum speed limit in the Universe. "With the development of fast-slewing ground-based telescopes such as the 0.6-m REM telescope at ESO La Silla, we can now...

290dcad9c3d851ba1c2f821e4a681bf81
2007-05-22 19:05:00

Using NASA's Swift satellite, astronomers have discovered that energetic flares seen after gamma-ray bursts (GRBs) are not just hiccups, they appear to be a continuation of the burst itself. GRBs release in seconds the same amount of energy our Sun will emit over its expected 10 billion-year lifetime. The staggering energy of a long-duration GRB (lasting more than a few seconds) comes from the core of a massive star collapsing to form a black hole or neutron star. In current theory, inrushing...

60d3a7b1a959daac8955992336a2ae071
2006-07-31 18:45:00

SANTA CRUZ, CA -- A survey of galaxies observed along the sightlines to quasars and gamma-ray bursts--both extremely luminous, distant objects--has revealed a puzzling inconsistency. Galaxies appear to be four times more common in the direction of gamma-ray bursts than in the direction of quasars. Quasars are thought to be powered by accretion of material onto supermassive black holes in the centers of distant galaxies. Gamma-ray bursts, the death throes of massive stars, are the most...

19c8e02eac3e9459a9d69c8aa3180e731
2006-04-18 12:45:00

COLUMBUS , Ohio -- Are you losing sleep at night because you're afraid that all life on Earth will suddenly be annihilated by a massive dose of gamma radiation from the cosmos? Well, now you can rest easy. Some scientists have wondered whether a deadly astronomical event called a gamma ray burst could happen in a galaxy like ours, but a group of astronomers at Ohio State University and their colleagues have determined that such an event would be nearly impossible. Gamma ray bursts (GRBs) are...

91ea79d9abd578b7f7590c3b7c4dce631
2006-01-31 14:58:07

Cambridge, MA -- Gamma-ray bursts are the most powerful explosions in the universe, emitting huge amounts of high-energy radiation. For decades their origin was a mystery. Scientists now believe they understand the processes that produce gamma-ray bursts. However, a new study by Jonathan Grindlay of the Harvard-Smithsonian Center for Astrophysics (CfA) and his colleagues, Simon Portegies Zwart (Astronomical Institute, The Netherlands) and Stephen McMillan (Drexel University), suggests a...


Latest Gamma-ray burst progenitors Reference Libraries

6_f3739d4b04b11a1c267bfcc286610ef92
2004-10-19 04:45:41

Hypernova -- A hypernova is a theoretical type of supernova produced when exceptionally large stars collapse at the end of their lifespan. In a hypernova, the core of the star collapses directly into a black hole and two extremely energetic jets of plasma are emitted from its rotational poles at nearly light speed. These jets emit intense gamma rays, and are a candidate explanation for gamma ray bursts. Theorists have come up with several plausible explanations for hypernovae. It may...

6_f5324ad7d5514381282c99963af8be7c2
2004-10-19 04:45:41

Gamma-Ray Burst -- In astronomy, Gamma-ray bursters (GRBs) are flashes of gamma rays that last from seconds to hours, the longer ones being followed by several days of X-ray afterglow. They occur at random positions in the sky several times each day. They are now believed to result from tremendous explosions in far away galaxies, during the creation of a black hole from a dying star or two colliding neutron stars. The black hole, surrounded by a rotating disk of matter falling into it,...

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Word of the Day
malpais
  • The ragged surface of a lava-flow.
'Malpais' translates from Spanish as 'bad land.'