  We calculate limits on the properties of neutrinos using data from gamma-ray
detectors on the Pioneer Venus Orbiter and Solar Max Mission satellites. A
massive neutrino decaying in flight from the supernova would produce gamma rays
detectable by these instruments. The lack of such a signal allows us to
constrain the mass, radiative lifetime, and branching ratio to photons of a
massive neutrino species produced in the supernova. Presented at Beyond The
Standard Model III, June, 1992.
