TITLE: GCN CIRCULAR NUMBER: 9693 SUBJECT: GRB 090717B: Fermi GBM detection DATE: 09/07/20 14:56:58 GMT FROM: Arne Rau at MPE Arne Rau (MPE) reports on behalf of the Fermi GBM Team: "At 02:40:31.79 UT on 17 July 2009, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 090717B (trigger 269491233 / 090717111). The on-ground calculated location, using the GBM trigger data, is RA = 247.0, DEC = 23.0 (J2000 degrees, equivalent to 16 h 28m m, 23 d 00 '), with an uncertainty of 3.9 degrees (radius, 1-sigma containment, statistical only; there is additionally a systematic error which is currently estimated to be 2 to 3 degrees). The angle from the Fermi LAT boresight is 35 degrees. This burst was also independently detected (although not triggered) by INTEGRAL SPI-ACS. The GBM light curve consists of a single peak with a duration (T90) of about 0.9 s (8-1000 keV). The time-averaged spectrum from T0-0.256s to T0+0.128 s is adequately fit by a simple power law function with index -1.02 +/- 0.04 (chi squared 604 for 732 d.o.f.). The event fluence (8-1000 keV) in this time interval is (4.83 +/- 0.03)E-07 erg/cm^2. The 0.384-sec peak photon flux measured starting from T0-0.256 s in the 8-1000 keV band is 3.91 +/- 0.42 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."