TITLE: GCN CIRCULAR NUMBER: 15477 SUBJECT: GRB 131108A: Fermi GBM observation DATE: 13/11/09 17:50:57 GMT FROM: George A. Younes at USRA/NASA/MSFC G. Younes (USRA/NASA-MSFC) reports on behalf of the Fermi GBM Team: At 20:41:55.76 UT on 08 November 2013, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 131108A (trigger 405636118/131108862), which also triggered onboard the Fermi/LAT (Racusin et al, GCN 15464). The GBM on-ground location is consistent with the Swift/XRT location of the candidate afterglow (M. C. Stroh and J. A. Kennea, GCN 15468). The burst was bright enough that it also resulted in an Autonomous Repoint Request (ARR). The GBM light curve consists of a multiple-peak structure with a duration (T90) of about 19 s (50-300 keV). The time-averaged spectrum from T0 to T0+21 s is adequately fit by a Band function with Epeak = 373 +/- 14 keV, alpha = -0.91 +/- 0.02, and beta = -2.6 +/- 0.1. The event fluence (10-1000 keV) in this time interval is (3.65 +/- 0.04)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+0.1 s in the 10-1000 keV band is 19.8 +/- 0.4 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog.