Astrophysical bounds on superlight gravitinos

We derive the allowed mass range for the superlight gravitino present in a large class of supersymmetric models from the observed neutrino luminosity from Supernova 1987A. We find that for photino masses of order of 100 GeV, the mass range 2.6 × 10−8eV ≤ mg ≤ 2.2 × 10−6eV for the gravitino g is excluded by SN1987A observations. Unlike the bounds on mg from nucleosynthesis, the bounds in the present paper do not depend critically upon the uncertainties of the observational input.