Supernova neutrinos are weakly interactive elementary particles produced during a core-collapse supernova explosion. A massive star collapses at the end of its life, emitting about ~ neutrinos and antineutrinos in all leptonic flavors. The luminosity of different neutrino and antineutrino species are roughly the same. They carry away about 99% of the gravitational energy of the dying star as a burst lasting tens of seconds. Their average energy is 10 − 20 MeV. Supernovae are considered the strongest and most frequent source of cosmic neutrinos in the MeV energy range.