TITLE: GCN GRB OBSERVATION REPORT NUMBER: 263 SUBJECT: GRB990217: BeppoSAX/GRBM data DATE: 99/02/22 19:56:01 GMT FROM: Filippo Frontera at ITESRE CNR L. Amati, F. Frontera and N. Masetti (ITESRE/CNR, Bologna), E. Montanari (University of Ferrara), E. Costa, M. Feroci and L. Piro (IAS/CNR) report on behalf of the BeppoSAX/GRBM Team: "The BeppoSAX Gamma Ray Burst Monitor detected GRB990217 (IAUC #7110) as a weak, single pulse gamma-ray burst lasting about 25 s. The total fluence in the 40-700 keV energy range is 4307 +/- 195 counts, corresponding to (1.3 +/- 0.2) x 10E-6 erg cmE-2. The 1 s peak flux in the same band is 146 +/- 43 counts/s, corresponding to (1.1 +/- 0.3) x 10E-7 erg cmE-2 sE-1. For a comparison, the peak flux in the 2-26 keV range as measured by the BeppoSAX/WFC N. 2 (IAUC #7110) is about 0.5 Crab, that corresponds to 1.64 x 10E-8 erg cmE-2 sE-1. The average photon index inferred from the GRBM data with the assumption of a single power-law is 1.52 +/- 0.55. The low statistical quality of the data does not allow to better constrain the spectral model." This message is citeable.