GCN Circular 13737
V.Chaplin (UAH) reports on behalf of the Fermi GBM Team: At 01:41:22.40 UT on 09 September 2012, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 120909A (trigger 368847685 / 120909070), which was also detected by the Swift/BAT (Immler et al. 2012, GCN 13727) The GBM on-ground location is consistent with the Swift position. The angle to the Fermi LAT boresight is 66 degrees. The GBM light curve consists of several peaks between T0 and T0+100 seconds, with a total duration (T90) of about 112 s (50-300 keV). The time-averaged spectrum from T0-2.8 s to T0+104.7 s is best fit by a power law with exponential cutoff having an index of -1.3 +/- 0.1 and cutoff energy 370 +/- 140 keV. The event fluence (10-1000 keV) in this time interval is (2.1 +/- 0.2)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+3.26 s in the 10-1000 keV band is 3.0 +/- 0.2 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog.