On February 23, 1987, at 7:35:35 UT, a neutrino burst was observed in the Kamiokande II detector during a 13-second interval. The signal consisted of eleven electron events with energies ranging from 7.5 to 36 MeV, with the first two events pointing back to the Large Magellanic Cloud (LMC) at angles of 18° ± 18° and 15° ± 27°. This burst was identified as a direct observation of neutrinos from supernova SN1987A, which was optically observed on February 24, 1987. The detection supports the current model of supernova collapse and neutron-star formation, providing valuable insights into neutrino properties and the solar-neutrino puzzle. The integral flux ofantineutrinos from the burst was estimated to be \(1.0 \times 10^{10} \bar{v}_{e} \, \mathrm{cm}^{-2}\), corresponding to a neutrino output of \(8 \times 10^{52} \, \text{ergs}\) for an assumed average energy of 15 MeV. This observation is the first direct evidence of neutrino astronomy and has significant implications for elementary-particle physics.On February 23, 1987, at 7:35:35 UT, a neutrino burst was observed in the Kamiokande II detector during a 13-second interval. The signal consisted of eleven electron events with energies ranging from 7.5 to 36 MeV, with the first two events pointing back to the Large Magellanic Cloud (LMC) at angles of 18° ± 18° and 15° ± 27°. This burst was identified as a direct observation of neutrinos from supernova SN1987A, which was optically observed on February 24, 1987. The detection supports the current model of supernova collapse and neutron-star formation, providing valuable insights into neutrino properties and the solar-neutrino puzzle. The integral flux ofantineutrinos from the burst was estimated to be \(1.0 \times 10^{10} \bar{v}_{e} \, \mathrm{cm}^{-2}\), corresponding to a neutrino output of \(8 \times 10^{52} \, \text{ergs}\) for an assumed average energy of 15 MeV. This observation is the first direct evidence of neutrino astronomy and has significant implications for elementary-particle physics.