TITLE: GCN CIRCULAR NUMBER: 28374 SUBJECT: GRB 200906A: Fermi GBM detection DATE: 20/09/07 00:03:11 GMT FROM: Christian Malacaria at NASA-MSFC/USRA R. Hamburg (UAH), C. Malacaria (NASA-MSFC/USRA) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 13:11:53.38 UT on 06 September 2020, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 200906A (trigger 621090718 / 200906550) which was also detected by the Swift/BAT and Swift/XRT (Page et al. 2020, GCN 28371). The Fermi GBM Final Real-time Localization (GCN 28370) is consistent with the Swift position. The angle from the Fermi LAT boresight at the GBM trigger time is 74 degrees. The GBM light curve shows two peaks with a duration (T90) of about 67.3 s (50-300 keV), starting at T0-49 s. The time-averaged spectrum from T0-4.1 s to T0+16.4 s is best fit by a Band function with Epeak = 50.5 +/- 9.9 keV, alpha = -1.1 +/- 0.2 , and beta = -2.1 +/- 0.1 The event fluence (10-1000 keV) in this time interval is (3.9 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+1.8 s in the 10-1000 keV band is 4.5 +/- 0.2 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/"