Axions and SN 1987A

We consider the effect of free-streaming axion emission on numerical models for the cooling of the newly born neutron star associated with SN 1987A. We find that for an axion mass of greater than ∼${10}^{\mathrm{-}3}$ eV, axion emission shortens the duration of the expected neutrino burst so significantly that it would be inconsistent with the neutrino observations made by the Kamiokande II and Irvine-Michigan-Brookhaven detectors. However, we have not investigated the possibility that axion trapping (which should occur for masses ≥0.02 eV) sufficiently reduces axion emission so that axion masses greater than ∼2 eV would be consistent with the neutrino observations.