Toward understanding gamma-ray bursts.

Gamma-ray bursts (GRBs) have puzzled astronomers since their accidental discovery in the sixties. The BATSE detector on the COMPTON-GRO satellite has been detecting one burst per day for the last four years. Its findings have revolutionized our ideas about the nature of these objects. The author shows that the simplest, most conventional, and practically inevitable, interpretation of the observations is that GRBs result from the conversion of the kinetic energy of ultra-relativistic particles (or possibly Poynting flux) to radiation in an optically thin region. The inner "engine" that accelerates these particles is optically thick and it is hidden from direct observations. Its origin may remain mysterious for a long time.