GRB and the atmosphere.

Forums General Discussion GRB and the atmosphere.

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    Dr Paul Leyland

    This might find a home in “Atmospheric Phenomena” but seems more appropriate here to me.

    Recently a high energy gamma ray burster, GRB 221009A, was detected by gamma ray telescopes (as one should expect), the detectors of some of which were overwhelmed by its intensity. As sometimes happens, the optical afterglow was also picked up by rapid-reaction teams. This one was so close and so bright that the gamma ray photons disturbed the Earth’s ionosphere enough to be easily detected. A nice report of the ionospheric detection is available at

    It seems possible to me that the incoming gammas could produce muon — antimuon pairs. The rest mass of a pair is 0.211 GeV. Those produced by a 10GeV photon live long enough to stand a decent chance of reaching the ground.

    Now, I see muon tracks on many of my exposures …

    More precise calculations and many images will be needed to see whether there is a statistically significant signal to be found by examining the number of muon tracks taken around the time of the GRB compared with an hour earlier or later.

    Perhaps we shouldn’t discard our images, even those which are darks, flats, or otherwise useless for conventional scientific analysis! Unfortunately I can not contribute because I wasn’t imaging at the time.


    Parallels with neutrino astronomy come to mind. Only 25 neutrinos were verified to have come from SN1987a, way into the needle in haystack territory. Small signals can be found if (a) they are there and (b) you look hard enough for them.

    • This topic was modified 1 year, 8 months ago by Dr Paul Leyland. Reason: Forgot to double the mass of a muon to account for pair production
    • This topic was modified 1 year, 8 months ago by Dr Paul Leyland. Reason: Then forgot to convert for an elctron mass of 0.512MeV. Doh!
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