If an accelerator of energetic ions turns on inside a new type II supernova while the shell is sufficiently thick, energetic secondary mesons will be produced by collisions in the expanding shell. These will decay to give rise to neutrinos of energies much larger than the deleptonization and thermal neutrinos emitted during the collapse itself. If the power in accelerated protons is comparable to the optical luminosity, there may be enough neutrinos to be detectable in existing underground detectors within the next few months.

• Received 16 March 1987

DOI:https://doi.org/10.1103/PhysRevLett.58.1695