Observations of Gamma-Ray Bursts of Cosmic Origin

Sixteen short bursts of photons in the energy range O.2-l.S MeV have been observed between 1969 July and 1972 July using widely separated spacecraft. Burst durations ranged from less than 0.1 5 to 30 5, and time-integrated flux densities from 1O- ergs cm-2 to 2 X 10- ergs cm-2 in the energy range given. Significant time structure within bursts was observed. Directional information eliminates the Earth and Sun as sources. Subject headings:gamma rays - X-rays - variable stars