TITLE: GCN CIRCULAR NUMBER: 9713 SUBJECT: GRB 090711: Fermi GBM detection DATE: 09/07/27 14:10:00 GMT FROM: Bill Paciesas at UAH Colleen A. Wilson-Hodge (NASA/MSFC) reports on behalf of the Fermi GBM Team: "At 20:23:22.92 UT on 11 July 2009, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 090711 (trigger 269036604 / 090711850). The on-ground calculated location, using the GBM trigger data, is RA = 139.6, DEC = -64.7 (J2000 degrees, equivalent to 09 h 18 m, -64 d 42 '), with an uncertainty of 1 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 13 degrees. The GBM light curve consists of multiple peaks with a duration of at least 100 s (8-1000 keV). The GBM detectors were turned off for SAA entry about 83 seconds after the trigger. The time-averaged spectrum from T0-20.992 s to T0+82.433 s is adequately fit by a power law function with an exponential high energy cutoff. The power law index is 1.3 +/- 0.1 and the cutoff energy, parameterized as Epeak, is 210 +/- 70 keV The event fluence (8-1000 keV) in this time interval is (1.17 +/- 0.16 )E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+1.536 s in the 8-1000 keV band is 4.2 +/- 0.6 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."