Hard emission at late times from SN 1987A

Using a model for the explosion that has been remarkably successful in predicting and explaining the evolution of SN 1987A during its first one and one-half years we calculate the future photometric evolution of the supernova in the UV-optical-IR, X-ray, and γ-ray bands using Monte Carlo techniques. Special attention is given to the contribution from radioactive isotopes other than ^56^Co, notably ^57^Co, ^44^Ti, and ^22^Na, and to the possible appearance, probably within the next year, of X-rays from an accreting magnetic neutron star at the center of the supernova. The signature of a radio pulsar like the Crab is also considered. In both cases the time history of the bolometric light curve may be a more sensitive diagnostic than the existence of either pulses or hard emission, but will become confused in the near future by contributions from the rare radioactivities. A source as faint as the pulsed emission of the Crab pulsar will never be discernable in the bolometric light curve. Pulsed hard emission is best sought near 30 keV near the end of 1989 (and thereafter), although more sensitive instrumentation than hitherto employed may be necessary.