B) A supernova neutrino burst is probably emitted isotropically, so the neutrino flux is spread over the whole surface of an expanding sphere - this means the flux drops quickly with distance (r^-2 law). Globular clusters are large, dozens of light years in size. If the SN is close, only a few white dwarfs would lie along the line of sight. If the SN is distant, the flux is low.
Don. I disagree on the isotropy of the prompt neutrino burst.
1.Core collapse type 2 supernovae leave barrel shaped remnants, not spherical, as you would expect if the explosion was spherically symmetric (M.J. Kesteven, R.N. Manchester, Molonglo, NSW, Australian Journal of Physics)..48 0f 60 remnants definitively barrels..4 possible)..circa 1985.
2. Most supernova remnants whether type 2's or type 1a's are devoid of pulsars (Manchester also)..less than 5 in ~ 400.
3. High transverse velocity pulsars are seen, not associated with any nearby remnant(Lyne, Harrison, Cordes), though to be fair, they oft outlive the fairly short-lived remnants, suggesting ejection. (original asymmetrical ejections suggested by Schlovskii...circa 1976)
4.Pulsar ejection is a fundamental effect due to parity effects which are present in all weak interactions....supernovae no exception. The largest neutrino fluxes, and the strongest magnetic fields that naturally occur.
5. The nascent pulsar "birth" is almost certain to be accompanied by an asymmetry in the prompt neutrino burst, the and as a consequence of the massive pulsar acceleration....a gravitational wave.
6. Use of type1a's as standard candles fallaciously ignores luminosity vs viewing angle of the barrel shaped ejecta (I spoke to people in a position to use the info many years ago) ~14yrs.
7. Here's a prediction. If the long GRB's are truly from "beamed" supernovae...in all likihood the beam points in the birthward direction of the pulsar, as the shock front ruptures. Early neutrino beaming from that area losing neutrino opacity in the core shock bounce should precede a long GRB by only a few seconds statistically. Somebody ought to see if SuperKamiokande, SNO, MontBlanc, Dumand, Borexino, are set to observe statistical twitching precedent to Long GRB's.by 1-10 seconds..No? Pete.