TITLE: GCN CIRCULAR NUMBER: 12573 SUBJECT: GRB 111117A: Fermi GBM observation DATE: 11/11/19 15:35:22 GMT FROM: Suzanne Foley at MPE S. Foley (MPE) and P. Jenke (UAH) report on behalf of the Fermi GBM Team: "At 12:13:42.03 UT on 17 November 2011, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 111117A (trigger 343224824 / 111117510) which was also detected by the Swift/BAT (Mangano et al. 2011, GCN 12559). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight is 12 degrees. Moreover, this burst was bright enough to result in a Fermi spacecraft autonomous rapid repoint (ARR) maneuver. The GBM light curve consists of two pulses with a duration (T90) of about 0.5 s (50-300 keV). The time-averaged spectrum from T0-0.128 s to T0+0.384 s is well fit by a power law function with an exponential high-energy cutoff. The power law index is -0.69 (+0.17/- 0.15) and the lower limit on the cutoff energy, parameterized as Epeak, is 370 keV. The event fluence (10-1000 keV) in this time interval is (6.7 +/- 0.2)E-07 erg/cm^2. The 1-sec peak photon flux measured starting from T0-0.128 s in the 10-1000 keV band is 2.8 +/- 0.2 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."