TITLE: GCN CIRCULAR NUMBER: 12806 SUBJECT: GRB 111222A: Fermi GBM observations DATE: 12/01/05 07:54:09 GMT FROM: Arne Rau at MPE Arne Rau (MPE) and Charles Meegan (USRA) report on behalf of the Fermi GBM Team: "At 14:51:55.02 UT on 22 December 2011, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 111222A (trigger 346258317 / 111222619). The burst was was also detected by the 3rd Interplanetary Network (Hurley et al. 2011, GCN 12714) and The GBM on-ground location is consistent with the IPN position. The angle from the Fermi LAT boresight is 136 degrees. Moreover, this burst was bright enough to result in a Fermi spacecraft autonomous rapid repoint (ARR) maneuver. The GBM light curve shows a single pulse with a duration (T90) of about 0.32 s (50-300 keV). The time-averaged spectrum from T0-0.064 s to T0+0.320 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.38 +/- 0.06 and the cutoff energy, parameterized as Epeak, is 725 +/- 45 keV. The event fluence (10-1000 keV) in this time interval is (1.502 +/- 0.034)E-05 erg/cm^2. The 64-msec peak photon flux measured starting from T0+0.0 s in the 10-1000 keV band is 60.2 +/- 3.4 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."