A core-collapse supernova - the explosive death of a massive star - is one of the most spectacular events in astronomy. Supernova 1987A was visible to the naked eye, despite being 160000 light years away in the Magellanic Cloud; the supernova of 1034, which created the Crab Nebula, was visible in daylight for 23 days and at night for nearly two years. Yet these spectacular light shows involve only 1% of the energy released by the exploding star: the remaining 99% is emitted in the form of neutrinos. This was verified in 1987 by the detection of about 20 neutrinos from SN 1987A, but if a core-collapse supernova were to occur in our own Galaxy, our modern - much larger - neutrino detectors would see thousands of neutrinos.
In this talk I wll explain why supernovae produce neutrinos (and why neutrinos are necessary to produce supernovae), how we detect them, and what we might learn from the next Galactic supernova.