TITLE: GCN CIRCULAR NUMBER: 18828 SUBJECT: GRB 160104A: Fermi GBM observation DATE: 16/01/05 03:25:03 GMT FROM: Eric Burns at U of Alabama R. Hamburg (UAH) and Hoi-Fung Yu (MPE) report on behalf of the Fermi GBM Team: "At 11:24:13.22 UT on 04 January 2016, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 160104A (trigger 473599457 / 160104475), which was also detected by the Swift/BAT (A. Melandri et al. 2016, GCN 18815). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight at the GBM trigger time is 104 degrees. The GBM light curve consists of one main peak with a duration (T90) of about 10 s (50-300 keV). The time-averaged spectrum from T0-3.200 s to T0+0.128 s is adequately fit by a simple power law function with index -1.7 +/- 0.1. The event fluence (10-1000 keV) in this time interval is (6.1 +/- 0.7)E-07 erg/cm^2. The 1-sec peak photon flux measured starting from T0-1.92 s in the 10-1000 keV band is 1.7 +/- 0.2 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."