TITLE: GCN CIRCULAR NUMBER: 12326 SUBJECT: GRB 110903A: Fermi GBM observation DATE: 11/09/04 01:59:26 GMT FROM: Sheila McBreen at MPE S. McBreen (UCD/MPE) and G. Fitzpatrick (UCD) report on behalf of the Fermi GBM Team: "At 02:39:34.42 UT on 03 September 2011, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 110903A (trigger 336710376 / 110903111), which was also detected by INTEGRAL (Mereghetti et al. 2011, GCN 12322) and Konus-Wind (Golenetskii et al. 2011, GCN 12323). The GBM on-ground location is consistent with the INTEGRAL position. The angle from the Fermi LAT boresight is 44 degrees. The GBM light curve shows/consists of 3 main emission phases with a duration (T90) of about 339.9 (+/-2.3)s (50-300 keV). The time-averaged spectrum from T0-0 s to T0+339 s is well fit by a power law function with an exponential high-energy cutoff. The power law index is -0.88 +/- 0.04 and the cutoff energy, parameterized as Epeak, is 281.3 +/- 21.1 keV. The event fluence (10-1000 keV) in this time interval is (3.3E-05 +/- 0.1)E-05 erg/cm^2. The 1.024-sec peak photon flux measured starting from T0+7.7 s in the 10-1000 keV band is 5.24 +/- 0.22 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."