ar X iv : a st ro - p h / 95 11 07 7 v 2 2 2 N ov 1 99 5 Long and Short GRB

We report evidence from the 3B Catalogue that short (T90 < 10 s) and long (T90 > 10 s) GRB represent different populations and processes: Their spectral behavior is qualitatively different, with short bursts harder in the BATSE range, but chiefly long bursts detected at higher photon energies; 〈V/Vmax〉 = 0.385 ± 0.019 for short GRB but 〈V/Vmax〉 = 0.282 ± 0.014 for long GRB, differing by 0.103 ± 0.024. Long GRB may be the consequence of accretion-induced collapse, but this mechanism fails for short GRB, for which we suggest colliding neutron stars.