Neutrinos from SN 1987A

Detections of neutrinos from SN 1987A by the Kamiokande II and IMB experiments (Hirata et al., 1987; Bionta et al., 1987) are analyzed by comparing them with the predictions of theoretical models of neutrino emission from stellar-core collapse. The observational data are summarized in a table; the fundamental principles underlying the model are discussed in detail; and the results are presented graphically. The model is found to predict the total energy, average neutrino energies (about 10 MeV), and burst duration (characteristic times of seconds, not milliseconds) with reasonable accuracy; hence the observations support the model hypothesis that neutrinos diffuse out of the collapsing core. An upper limit of 6.5 eV for the neutrino mass is derived.