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: You said: : >Neutrino bursts from Supernovae interacting with matter in stars should produce reactions giving a burst of gamma photons from the surface. : Ok, this idea is completely wrong from an astrophysics standpoint. It simply doesn't work this way. Two protons fuse, under ideal conditions, producing a deuterium nucleus, a positron and an electron neutrino. Next, a deuterium nucleus and another proton fuse, producing a gamma photon, and a light helium atom. Two helium isotopes react creating a neutral helium atom, two protons and a gamma ray photon. : In a supernova explosion, protons and electrons are combined to make neutrons and neutrinos. The neutrinos carry off the vast amounts of energy produced by the collapse of the stellar core. The neutrinos _do not_ interact with matter to produce gamma radiation. In fact, if you're lucky, neutrinos _may_ produce Cerenkov radiation showing up as a faint flash of light within the proper environment and material. The number of neutrinos detected from SN1987a was under 1,000 while the theoretical output was 10^57. The detection was not even noticed at Kamiokande and Sudbury until the following day. : >I was trying to get the idea over in a few words by describing them as radar echos. : Radar may actually be closer to the wavelength you might detect a neutrino interaction. As I said before, an interaction will be reradiated at a frequency that's lower than the initial frequency. Gamma rays reradiate in x-rays, x-rays reradiate in the ultraviolet, ultraviolet reradiates in the visible visible in infrared etc. It's high school physics. : >I started thinking only about neutron stars but the article in Sky & telescope feb 1998 with its profiles of bursts suggested white dwarfs as well. : I'll have to look that one up. I recall the article, but not the specifics. : Anyway with some spherical trigonometry to get the angle between a star and the supernova, you might find further proof. I cannot make sense of the data on the Interplanetary Network but it is supposed to give precise directions to bursts. : The IPN uses the arrival times of gamma rays from several satellites to determine the direction and intensity of the origin of the grb. Ulysses, KONUS wind, BeppoSAX, Mars Odyssey and others have gamma ray detectors aboard. In fact, basically every satellite launched since 1995 has had a gamma detector of some kind aboard. Being widely spaced, it makes it realtively easy to triangulate the origin of a gamma ray burst using the arrival time of the burst energy. : >If these directions match the position of a local star and its approx distance agrees with a hit from a supeernova then you have it. : So far, they do not match. There was one GRB last year that may be linked to a supernova in a distant galaxy. One. Distant-700 million LY. : : >Please note that the 1006 AD supernova was very close so that ordinary stars might produce detectable bursts. : Again, faulty physics. : And this is not to say that the measurement of cosmological distances to some afterglows was wrong. This is just an extra possibility. Who says that gamma bursts have only one explanation? : Certainly not me. It's just that the most well studied bursts so far all point to distant origins, except on that I'm aware of, one from the LMC in and it turned out to be a soft gamma repeater, a completely different animal.

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