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Short Gamma-ray Bursts Traced to Colliding Stars 135

Posted by samzenpus
from the stars-smash dept.
Astervitude writes "Collisions of the cosmic kind could be the source of one of nature's most lethal explosions. Astronomers have traced the origin of short-duration gamma-ray bursts, or GRBs, to the merger of neutron stars or other dense bodies. Space.com has a report on the scientific detective work that led to the solution of what has been described as a 35-year-old mystery. "Our observations do not prove the coalescence model, but we surely have found a lady with a smoking gun next to a dead body," said Shri Kulkarni, one of over two dozen astronomers who discovered and investigated two short-duration bursts that took place last May and July. Unlike short-duration GRBs, long-duration GRBs are believed to be produced when extremely massive stars collapse and explode as supernovas."
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Short Gamma-ray Bursts Traced to Colliding Stars

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  • The Science Channel (Score:4, Interesting)

    by Namronorman (901664) on Thursday October 06, 2005 @01:18AM (#13727689)
    The Science Channel has recently (by coincidence?) been showing a lot of programs talking about stars and the sun, and a very common topic has been Gamma Ray Bursts.

    I just think it's weird how some things seem like a trend some times.

    The idea of neutron stars colliding is a very old theory but this seems to shed new light on the possibility of it being the main cause.
    • by Zindagi (875849)
      One of the reasons that comes to mind is the launch of a new satellite for observing GRBs SWIFT [nasa.gov]. And the fact that GRB's are intrinsically intriguing - being the huge balls of energy (if you will) in the Universe
  • Correction... (Score:2, Interesting)

    by Adi42 (920652)
    It's actually about colliding neutron stars...

    Anyway, it is curious that no gamma-ray bursts occured in our galaxy (yet). It is supposed that such an even would generate enough gamma rays to wipe out the ozone layer, and cause life extinction on earth.

    Wait... why dinosaurs dissapeared again? :-)
    • Anyway, it is curious that no gamma-ray bursts occured in our galaxy (yet). It is supposed that such an even would generate enough gamma rays to wipe out the ozone layer, and cause life extinction on earth.

      Wait... why dinosaurs dissapeared again? :-)


      I thought it was because they took up smoking...
    • Correct me if I'm wrong, but didn't dinosaurs extinct over a period of time, long enough to evolve and adapt to changing environment?

      And not only that, extinction in mass scale doesn't seem to "sanitize", but "life" seems to find its way out of harsh environment or adapt. Matter of fact, didn't theropod dinosaur survive? After all, what are all these birds doing on earth?
      • Correct me if I'm wrong, but didn't dinosaurs extinct over a period of time, long enough to evolve and adapt to changing environment?

        No. Many species of dinosaur became extinct of a period, but at a slow rate. The latest evidence is that the final extinction which wiped out the rest was very fast indeed.

        And not only that, extinction in mass scale doesn't seem to "sanitize", but "life" seems to find its way out of harsh environment or adapt. Matter of fact, didn't theropod dinosaur survive? After all, wha
    • Re:Correction... (Score:3, Informative)

      by Decaff (42676)
      Anyway, it is curious that no gamma-ray bursts occured in our galaxy (yet).

      They may have, but not pointed in our direction.

      It is supposed that such an even would generate enough gamma rays to wipe out the ozone layer, and cause life extinction on earth.

      Wiping out the ozone layer would not cause extinction of life, after all, life survived for billions of years without such a layer.
    • It is supposed that such an even would generate enough gamma rays to wipe out the ozone layer, and cause life extinction on earth.



      If the burst occurs close enough (a few lighyears, maybe even a few tens of lightyears should do), it would essentially sterilize the side of the planet that is facing towards the source of the burst.



      Death Stars are for tourists.

    • Did you read the article at all ?

      This gamma ray burst was from within our galaxy !

      A GRB of this size within 10 light years would be enough to disrupt (read species die out) on earth.
      The nearest worrying sources, magnetars, around 4000-5000 light years away.

      Please, please, please, do a little google searching before opening your mouth.
      • No. The two GRB's they are interested in were about 1 billion light years away -- well outside our galaxy, but closer than the regaular long-duration GRBs which are several billion lys away.

        You may be confusing this with the recent outburst from (probably) a magnetar on the other side of the galaxy, which is a Soft Gamma Repeater (SGR), a different thing again.
      • the article specifically says: "Astronomers now know the event took place on the outskirts of a faraway galaxy, a location where old stellar remnants like neutron stars are known to reside." 'Faraway galaxy' doesn't sound like it was our galaxy
      • magnetars [wikipedia.org] are way cool:

        A magnetic field above 10 gigateslas is strong enough to wipe a credit card from half the distance of the Moon from the Earth. A small neodymium based rare earth magnet has a field of about a tesla, Earth has a geomagnetic field of 30-60 microteslas, and most media used for data storage can be erased with a millitesla field.

        The magnetic field of a magnetar would be lethal at a distance of up to 1000 km, tearing tissues due to the diamagnetism of water.

    • So with a Gamma-ray burst it caused all the Mammals into huge green invincible creatures that killed all the dinosaurs when they got angry.... Cool.

      TRex to Big mouse thinggy. I am going to eat you.
      Mouse: I am getting angrrrrrrryyy. Rarrrr! Mouse Smash!!
      THen the mouse beats up the TRex
    • I've read somewhere that if one happened less that 6000 light years away, we're screwed. The half of the planet within line of sight of the event would be sterilized and the ozone on that half would disappear. Over the next few days the ozone left would disperse evenly, so whoever lived would have half the ozone layer. Crop loss, skin cancer, environmental devastation and other hilarity would ensue.
    • Anyway, it is curious that no gamma-ray bursts occured in our galaxy (yet). It is supposed that such an even would generate enough gamma rays to wipe out the ozone layer, and cause life extinction on earth.

      Where were you last December? The most luminous gamma ray event in the history of measurement occurred based on a gamma ray burst on the other side of our own galaxy. That particular event was cause by starquake and crustal reorganization of a magnetar, a rare type of event expected to explain a small p
  • Gravity Waves (Score:4, Informative)

    by williwilli (639147) on Thursday October 06, 2005 @01:38AM (#13727758) Homepage
    The end part of the article notes that the upcoming LIGO observatory might see the first detection of gravitational waves, corresponding with a GRB event! Evidentially Einstein modeled the emission of gravity waves during a collision between Neutron stars. This is interesting because we don't really know much about gravity; e.g. if it is a wave or a constant. More info on LIGO is available here. [caltech.edu]

    free music, games, recipes, and more! [earth2willi.com]
    • Re:Gravity Waves (Score:3, Informative)

      by Decaff (42676)
      This is interesting because we don't really know much about gravity; e.g. if it is a wave or a constant.

      We are pretty sure it is a wave because we have seen the effects of gravitational radiation (of waves) in double neutron star orbits. If gravity isn't waves, then general relativity is in trouble, which is unlikely.
    • Re:Gravity Waves (Score:3, Informative)

      by PhilRod (550010)

      The paper itself suggests that observing the waves from such an event would have to wait until the "second generation" LIGOs. I assume by that it means advanced LIGO [caltech.edu], which isn't scheduled to start taking measurements until 2013, so don't hold your breath :-). Even so, LIGO is an amazing project - the sensitivities required are enormous, (to quote the LIGO website: "These changes are minute: just 10-16 centimeters, or one-hundred-millionth the diameter of a hydrogen atom over the 4 kilometer length of the

    • LIGO is not just "upcoming". It's already running, though not 24x7x365, and taking data. You can see some of the early papers at the preprint archive [arxiv.org]: search for "LIGO" in the author field.
  • Would the explosion at the end have be when the majority of the neutron star mass hits the black hole's event horizon?
    • by Anonymous Coward
      No. In fact, nothing would be seen: the horizon is not a physical surface that a star can "smack into", but a region of space within which light can't escape. In fact, that is one of the main new ways we have found to justify the existence of black holes: when things run into them and you don't see a big flash from a collision.
  • by Mathinker (909784) on Thursday October 06, 2005 @02:20AM (#13727852) Journal

    The merger of two dense bodies causes gamma-ray bursts?

    Wow! Now I can get rich selling lead underwear the next time there's a Microsoft/AOL merger hoax [re-quest.net]

  • by MooseByte (751829) on Thursday October 06, 2005 @02:59AM (#13727941)

    "Our observations do not prove the coalescence model, but we surely have found a lady with a smoking gun next to a dead body," said Shri Kulkarni

    Looks like the Sin City [imdb.com] DVD has been getting a lot of play time down in the lab....

  • Collisions of the cosmic kind could be the source of one of nature's most lethal explosions

    Amazing! And here I thought collisions of the microscopic kind caused the most lethal explosions...
  • by MAdMaxOr (834679) on Thursday October 06, 2005 @03:20AM (#13727981)
    What is the typical frequency? (i.e. 1x per galaxy per 100k years)
    What is a typical duration?
    How close would you have to be to one to receive a lethal radiation dose?
    • a) Not many, SWIFT detects between 30 and 300 a year, only a handful a year from our galaxy (I think)
      b) From less than a second, to a few seconds. VERY brief.
      c) A decent magentar flare or decent neutron merger within 10 light years would be enough to disrupt life (read species would die out)

      The nearest magnetars are 4000-5000 light years away.

      It does beg the question thoughL Which poor people got burned on this burst ?
      • If there were "a few per year" from our galaxy, live would have never evolved on earth... (just think about it: a few per year over the the time earth exists is about 10 billion GRBs ....

        I dont know if we _EVER_ have observed a GRB in our galaxy, the detected ones are very isotropically distributed over the sky and in the _deep_ background. Most have a z>0.1 and are FAR away.

        And the killing ratio for a GRB would be more like 100-250 ly. 10 ly away even a normal supernova would be an extinction event.

        Just
        • I do research in X-ray and Gamma-Ray astronomy and just wanted to confirm that so far no gamma-ray bursts have ever been observed to come from our own galaxy.
          • I do research in X-ray and Gamma-Ray astronomy and just wanted to confirm that so far no gamma-ray bursts have ever been observed to come from our own galaxy.

            Forgive me, but have you been living under a rock the last year? SGR 1806-20 [wikipedia.org] gave rise to a gamma ray burst last December which was the most lumninous event recieved at Earth in the history of gamma ray astronomy, and it was only 50,000 light years away at the other side of our galaxy.

            I'll admit, magnetar star quakes aren't as sexy as high end superno
  • The summary (Score:2, Interesting)

    by barath_s (609997)
    I liked the FAQ :
    http://www.astro.caltech.edu/~ejb/faq.html [caltech.edu]

    especially the portion that said ...." In practice, over the few seconds that a gamma ray burst occurs, it releases almost the same amount of energy as the entire Universe! " The article posted on Slashdot is on the short and hard type

    • Re:The summary (Score:4, Insightful)

      by Decaff (42676) on Thursday October 06, 2005 @05:13AM (#13728243)
      especially the portion that said ...." In practice, over the few seconds that a gamma ray burst occurs, it releases almost the same amount of energy as the entire Universe! "

      Which is, of course, nonsense. It should say 'the same amount of energy as the visible Universe'. Big (very, very big) difference!
  • Just been reading a brief history of time, 10th anniversary edition today. And i could swear this is spoken about in the book.

    Then again I could be wrong, a lot of it is over my head.
    • Just been reading a brief history of time, 10th anniversary edition today. And i could swear this is spoken about in the book.

      It is. Gamma-ray bursts have been observed for a long time: they were first discovered by spysats designed to watch out for nuclear test ban violations. ISTR that it was initially thought that the Soviets were trying to evade the ban by testing in deep space, but it soon became clear that these explosions were from much further afield.

      The collision of neutron stars has always bee

  • by snookums (48954) on Thursday October 06, 2005 @04:48AM (#13728188)
    ...with the Electric [the-electr...verse.info] Universe [holoscience.com] theory?
  • How long do you think before God posts the MPEGs on his web site?

    Actually I have a pretty good idea of what's on his site looks like. They'll be somewhere between pages about playing with metallic sodium and his beer recipes.
  • Astronomers have traced the origin of short-duration gamma-ray bursts But I'd be pretty warry about making anyone from that region of space angry.

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