Neutrinos Carry the Hidden Energy of Core-Collapse Supernovae

Core-collapse supernovae emit the vast majority of their energy as neutrinos rather than light—about 99% versus 0.1–1% in photons—because electron capture in the collapsing core produces neutrinos that escape with little interaction. This neutrino burst powers the explosion and confirms the energy budget, as demonstrated by SN 1987A's detections; with detectors like Hyper-Kamiokande and IceCube, a future galactic SN would yield millions of neutrinos, making neutrinos the primary energy carrier in these events.