We reanalyze the neutrino events from SN1987A in IMB and Kamiokande-II ( KII ) detectors , and compare them with the expectations from simple theoretical models of the neutrino emission .
In both detectors the angular distributions are peaked in the forward direction , and the average cosines are 2 sigma above the expected values .
Furthermore , the average energy in KII is low if compared with the expectations ; but , as we show , the assumption that a few ( probably one ) events at KII have been caused by elastic scattering is not in contrast with the ’ standard ’ picture of the collapse and yields a more satisfactory distributions in angle and ( marginally ) in energy .
The observations give useful information on the astrophysical parameters of the collapse : in our evaluations , the mean energy of electron antineutrinos is \langle E \rangle = 12 - 16 MeV , the total energy radiated around ( 2 - 3 ) \times 10 ^ { 53 } erg , and there is a hint for a relatively large radiation of non-electronic neutrino species .
These properties of the neutrino burst are not in disagreement with those suggested by the current theoretical paradigm , but the data leave wide space to non-standard pictures , especially when neutrino oscillations are included .