Neutrino oscillations, biased by the magnetic field, alter the shape of the neutrinosphere in a cooling protoneutron star emerging from the supernova collapse. The resulting anisotropy in the momentum of outgoing neutrinos can be the origin of the observed proper motions of pulsars. The connection between the pulsar velocities and neutrino oscillations results in a prediction for the τ neutrino mass of $m\left({\nu }_{\tau }\right)\sim 100\mathrm{eV}$.

• Received 26 June 1996

DOI:https://doi.org/10.1103/PhysRevLett.77.4872