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Do supernovae emit gamma rays?

  1. Oct 4, 2007 #1
    Do all types of supernovae emit gamma rays? If so, is it an initial burst, or does the GRB last as long as the visible light? If so, is the GRB in all directions or just in jets? Thanks.
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  3. Oct 5, 2007 #2


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    All stars emit gamma rays and X-rays, which is inherent in the nuclear and atomic processes within a plasma in which fusion takes place. Gamma rays bursts are simply an intense burst of gamma related to the extremely high power levels in the supernova phenomenon. It's possible that there is some direction dependence on gamma ray intensity, but off-hand I'm not sure what that would be.

    The gamma rays burst/pulse should coincide with the visible light, but remember there is a distribution of frequencies and the peak shifts as a function of time. Visible light is emitted continuously.

    See - http://science.nasa.gov/newhome/headlines/ast27jan99_1.htm

    Jan 27, 1999: For the first time, scientists have witnessed the visible light emitted at the same time as a gamma-ray burst, a mysterious explosion in the far reaches of the universe.

    The visible light is intense even after the GRB.
    Caltech observes brightest gamma-ray burst so far

  4. Oct 5, 2007 #3
    Thanks. But what I'm really interested in is whether a nearby supernova could damage the ozone layer. The History channel resently had a show that described how a GRB might destroy the ozone layer and all the consequences that followed. Then I remembered a similar show narated by Patric Steward describing the same effects with a nearby supernova. I was just wondering how close a nearby supernova would have to be in order to cause those effects. Does anybody recall the show or know about such things? Thanks.
  5. Oct 5, 2007 #4


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    For a regular supernova the distance is 10-20 light years. ie very very close in galactic terms, the 10,000 light years is for a GRB which are M times more energetic.
  6. Oct 5, 2007 #5


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    There is certainly concern that a nearby SN could do a lot of damage to the Earth. One would have to determine a rad dosage that would damage the ozone layer or irradiate the earth's surface, then use the source strength to determine the closest safe distance based on 1/r2 reduction in strength.

    Recently (Dec 27, 2004) there was a GRB, which was the brightest one recorded to date.

    Brightest Explosion Ever Observed Overwhelms Telescopes
    So it was in our solar system, 50 kly from earth.



    http://www.gsfc.nasa.gov/topstory/20021030strongestmag.html ( 2 yrs before explosion of Dec 2004)

    An exceptionally bright flare from SGR 1806−20 and the origins of short-duration -ray bursts

    SGR 1806-20 Sudden Ionospheric Disturbance

    SGR 1806-20 -- Pulsar

    Massive Stars in the SGR 1806-20 Cluster
    Last edited: Oct 5, 2007
  7. Oct 5, 2007 #6


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    Staff: Mentor

    Some other material of interest -


    Using Swift observations of prompt and afterglow emission to classify GRBs

    Long Burst Supernovae

    Hybrid GRB 060614: A Long Gamma-Ray Burst Without a Supernova


    ESA's INTErnational Gamma-Ray Astrophysics Laboratory is detecting some of the most energetic radiation that comes from space. It is the most sensitive gamma-ray observatory ever launched. INTEGRAL is an ESA mission in cooperation with Russia and the United States.

    Diversity of the Supernova - Gamma-Ray Burst Connection by Nomoto, Tominaga, Tanaka, Maeda, Suzuki, Deng, and Mazzali. To be published in the proceedings of the conference "SWIFT and GRBs: Unveiling the Relativistic Universe", Venice, June 5-9, 2006. Should be in Il Nuovo Cimento


    Simulations of Magnetically-Driven Supernova and Hypernova Explosions in the Context of Rapid Rotation

    Supernova Nucleosynthesis in Population III 13 -- 50 $M_{\odot}$ Stars and Abundance Patterns of Extremely Metal-Poor Stars
  8. Oct 7, 2007 #7
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