TITLE: GCN CIRCULAR NUMBER: 15315 SUBJECT: GRB 131004A: Fermi GBM observation DATE: 13/10/06 02:20:22 GMT FROM: Shaolin Xiong at UAH Shaolin Xiong (UAH) reports on behalf of the Fermi GBM Team: "At 21:41:03.68 UT on 04 October 2013, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 131004A (trigger 402615666 / 131004904), which was also detected by the Swift/BAT (Hagen et al. 2013, GCN 15303). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight is 93 degrees. The GBM light curve consists of multiple pulses with a duration (T90) of about 1.4 s (50-300 keV). The time-averaged spectrum from T0-0.19 s to T0+0.58 s is well fit by a simple power law function with index -1.75 +/- 0.06. The event fluence (10-1000 keV) in this time interval is (6.2 +/- 0.6)E-7 erg/cm^2. The 64 ms peak photon flux measured starting from T0+0.192 s in the 10-1000 keV band is 10.4 +/- 1.6 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."