TITLE: GCN CIRCULAR NUMBER: 28830 SUBJECT: GRB 201104A: Fermi GBM observation DATE: 20/11/04 20:51:58 GMT FROM: Christian Malacaria at NASA-MSFC/USRA E. Bissaldi (Politecnico and INFN Bari) and C. Malacaria (NASA-MSFC/USRA) report on behalf of the Fermi GBM Team: "At 00:00:56.75 UT on 4 November 2020, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 201104A (trigger 626140861 / 201104001, which was also detected by the Fermi-LAT (Ohno et al. 2020, GCN 28828) and AGILE (Ursi et al. 2020, GCN 28829). The GBM on-ground location is consistent with the LAT position. The angle from the Fermi LAT boresight at the GBM trigger time is 57 degrees. The GBM light curve shows a bright emission episode with a duration (T90) of about 8.4 s (50-300 keV). The time-averaged spectrum from T0 to T0+9 s is best fit by a Band function with Epeak = 1140 +/- 130 keV, alpha = -0.76 +/- 0.04, and beta = -2.24 +/- 0.17. The event fluence (10-1000 keV) in this time interval is (1.55 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0 in the 10-1000 keV band is 12.1 +/- 0.3 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"