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: Ok, now I see. You're talking about a burst of gamma rays from some event or another. These are completely different from the gamma ray bursts I'm talking about. : The burst of neutrinos detected after the SN1987A were the result of the explosion of the star in the Large Magellanic Cloud, (LMC) and while gamma rays were emitted and detected from this event, (although not by BATSE which wasn't launched until 1991 aboard the Compton Gamma Ray Observatory, unless you're talking about the balloon experiments previous to CGRO, although these were not flying when SN1987a occurred, to the best of my knowledge), they were of insufficient energy to be called a gamma ray burst, GRB. This was simply a supernova. Neutrinos are not gamma rays. : A gamma ray burst is a sudden, random burst of very high energy gamma rays, on the order of 250-500meV from some place in space. These events occur on average once per day, last from tenths of a second to a couple minutes and all but disappear within hours. I'd recommend the book, "The Biggest Bangs" by Jonathan I. Katz as a primer. : >Neutrinos from 1987a were detected after coming 160,000 light years. : You should add "only" to 160,000 ly. Redshifts to several possible host galaxies of GRB's measured by HST, Keck and others since roughly 1998 have put the distances in the neighborhood of 1 billion to 4 billion light years and higher. GRB's have been all but proven to be at cosmological distances, not local. See "The Great Debate", Lamb v. Paczynski, 1995. : >There have been 5 closer supernovae in the last 1000 years. uming equivalent neutrino emission they would be more intense by the ratio of the squares of distances. : So? As I said, neutrino detection is difficult at best. Read any of the current literature and the detection of neutrinos from our own Sun is difficult. What do neutrinos have to do with gamma rays? : >These bursts are moving away beyond Earth and encountering stars. Now I have identified two possible gamma bursts from local white dwarfs caused by the 1987a neutrinos. (from the BATSE 4b catalog). : To which bursts by trigger number are you referring? Can you tell me which "local white dwarfes" by HD, HR or SAO catalog number? I can do some research for you to verify, if you like. As I said, gamma ray bursts are not caused by the interaction of neutrinos with ordinary matter, nor are they caused by interaction with exotic matter, such as that found in neutron stars. The physics does not support it. Besides, even if neutrinos interacted with matter energetically, which they don't, any measured radiation would be measured as being reradiated at a lower energy, not higher. : >But I am puzzled because at the time of 1987a, gamma ray detectors in space might have detected a gamma burst from the Sun. : Gamma rays are detected from the Sun all the time, but more often high energy, (very fast moving) protons are what's acually being measured. All of the gamma radiation produced by the Sun occurs in its core. But by the time it escapes the core it has been buffeted about, absorbed and reradiated as lower energy photons for nearly a million years. : >( also the moon, planets and the ground beneath our feet but these very weak). : This is basically accepted as background noise or cosmic rays, or both, not "emission" of gamma rays by these entities. : >So I wonder if the data was ysed properly. : Of this, you can rest ured. Many minds better than mine have spent carreers waiting for the chance to yze such data. I'm fairly sure they got it right. : >Things have been missed before. : Not in this case, I'm afraid. : > If there was such a burst it would be the most local one so far and surprize, surprize we are still here. : I'm not to sure what your point is here, but I'm not surprised at all we're still here, given the protection from gamma rays ured by our own atmosphere and the distance to these energetic bursts. : Please use the new message board at: : http://killdevilhill.com/astronomychat/wwwboard.html : I own and operate a small observatory in SW AZ where I educate the public and do variable star research, including GRBOptical Transient searches.

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