TITLE: GCN CIRCULAR NUMBER: 22123 SUBJECT: GRB 171112A: Fermi GBM Detection DATE: 17/11/14 21:46:06 GMT FROM: Matthew Stanbro at UAH/Fermi M. Stanbro, R. Hamburg, and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 20:50:17.15 UT on 12 November 2017, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 171112A (trigger 532212622 / 171112868) which was also detected by the MAXI/GSC (Sugita et al. 2017, GCN 22118) The GBM on-ground location is consistent with the MAXI position. The angle from the Fermi LAT boresight at the GBM trigger time is 99 degrees. The GBM light curve consists of multiple episodes with a duration (T90) of about 145 s (50-300 keV). The time-averaged spectrum from T0-45.44 s to T0+104.07 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.49 +/- 0.06 and the cutoff energy, parameterized as Epeak, is 198 +/- 38 keV. The event fluence (10-1000 keV) in this time interval is (1.75 +/- 0.06)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+1.73 s in the 10-1000 keV band is 6.50 +/- 0.31 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."