Prospects for observations of nucleosynthetic gamma-ray lines and continuum from SN 1987A.

Expected flux levels for nucleosynthetic gamma-ray line and continuum emission from SN 1987a are calculated for several models of the event. The dominant line emission is from freshly synthesized sup (56) Ni and its decay daughters. The gamma- ray continuum is from Compton scattering of line photons. We set a lower limit on the amount of sup (56) Ni produced of 0.02 Mg, based on the hypothesis that the optical light curve is driven by radioactive heating. For a 15 Mg Type II model with 1.3 x 10 sup (51) ergs of kinetic energy and 0.1 Mg of sup (56) Ni, the light curve for the 0.847 MeV gamma- ray line peaks 550 days after onset (in August 1988) at a level of 3 x 10 sup (-4) photons cm sup (-2) s sup (-1). This is detectable only by new ultrasensitive balloon-borne spectrometers that are in final preparations for flight.