TITLE: GCN GRB OBSERVATION REPORT NUMBER: 443 SUBJECT: GRB991106: the first BeppoSAX short GRB detection? DATE: 99/11/09 16:47:36 GMT FROM: Giangiacomo Gandolfi at IAS/CNR Frascati GRB991106: the first BeppoSAX short GRB detection? G.Gandolfi, E.Costa, Istituto di Astrofisica Spaziale (IAS)/CNR, Roma, L. Di Ciolo, G.Tarei, BeppoSAX Scientific Operation Centre, Telespazio, Roma, M.J.S. Smith, J. In't Zand, Space Research Organization of the Netherlands (SRON), Utrecht, report: "The BeppoSAX Gamma Ray Burst Monitor (GRBM) and Wide Field Camera (WFC unit 1) observed an untriggered, faint and possibly short gamma-ray burst on November 6.4545 UT. A preliminary analysis reveals a duration of about 1 s in the GRBM, with a peak photon countrate of 120 cts/s in the 40-700 keV energy band. In the WFC, the duration is about 5 s and the peak flux is 0.3 Crab (2-26 keV). The position of the X-ray counterpart is R.A. = 22h24m49s Decl. = +54d21'.9 (equinox 2000.0) with an 99% error radius of 3.2'. An analysis of the 70 ksec NFI follow-up, performed about 8 hours after, is being carried on." #----------------------------------#------------------------------------------# Giangiacomo Gandolfi | E-mail: Istituto Astrofisica Spaziale | gandolfi@hal9000.ias.rm.cnr.it C.N.R. | Via Fosso del Cavaliere | phone: -39-06-4993-4005 I-00133 Roma | Italy | fax(CNR) : -39-06-20660188 #__________________________________#__________________________________________#