Neutrino masses and flavors emitted in the supernova SN1987A

The analysis of the energies and times of arrival of neutrino events in the Kamioka and Irvine-Michigan-Brookhaven detectors yields two mass groupings at {~}22 eV and the other at {~}4 eV, if all neutrinos were released rapidly at the supernova. A preliminary assignment of flavors to the neutrinos producing these events is attempted; this is beset with problems unless there is mixing and ν_τ are emitted more copiously than νₑ. Large statistical and systematic uncertainties necessitate caution in assessing this interpretation.