TITLE: GCN CIRCULAR NUMBER: 18582 SUBJECT: GRB 151111A: Fermi GBM observation DATE: 15/11/11 21:23:12 GMT FROM: Elisabetta Bissaldi at U.Innsbruk/IAPP E.Bissaldi (INFN Bari) and P.N. Bhat (UAH) report on behalf of the Fermi GBM Team: "At 08:33:20.03 UT on 11 November 2015, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 151111A (trigger 468923604 / 151111356), which was also detected by the Swift/BAT (McCauley et al. 2015, GCN 18578). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight at the GBM trigger time is 50 degrees. The GBM light curve consists of a single FRED-like episode with a duration (T90) of about 40 s (50-300 keV). The time-averaged spectrum from T0-2 s to T0+30 s is adequately fit by a power law function with an exponential high-energy cutoff. The power law index is 0.0 ± 0.2 and the cutoff energy, parameterized as Epeak, is 107 ± 8 keV. The event fluence (10-1000 keV) in this time interval is (2.05 ± 0.13)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+0.2 s in the 10-1000 keV band is 1.41 ± 0.17 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."