GCN Circular 28874
C. Malacaria (NASA-MSFC/USRA) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 02:31:05.79 UT on 9 November 2020, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 201109A (trigger 626581870 / 201109105). The Fermi GBM Final Real-time Localization was reported in GCN 28868. The angle from the Fermi LAT boresight at the GBM trigger time is 66 degrees. The GBM light curve consists of a bright peak with a duration (T90) of about 0.45 s (50-300 keV). The time-averaged spectrum from T0-0.128 s to T0+0.384 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.61 +/- 0.11 and the cutoff energy, parameterized as Epeak, is 318 +/- 41 keV. The event fluence (10-1000 keV) in this time interval is (9.55 +/- 0.72)E-07 erg/cm^2. The 64-msec peak photon flux measured starting from T0+64 ms in the 10-1000 keV band is 18.4 +/- 1.2 ph/s/cm^2. A Band function fits the spectrum equally well with Epeak= 304 +/- 56 keV, alpha = -0.59 +/- 0.14 and beta = -2.93 +/- 1.42 . 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/"