TITLE: GCN CIRCULAR NUMBER: 28287 SUBJECT: GRB 200826A: Fermi GBM observation DATE: 20/08/26 17:18:41 GMT FROM: Joe Mangan at UCD J.Mangan (UCD), R.Dunwoody (UCD) and C.Meegan (UAH) report on behalf of the Fermi GBM Team: "At 04:29:52.57 UT on 26 August 2020, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 200826A (trigger 620108997 / 200826187). The on-ground calculated location, using the GBM trigger data, was reported in GCN 28284. The GBM light curve shows an exceptionally bright short GRB with a duration (T90) of about 1.14 s (50-300 keV). The time-averaged spectrum from T0-0.29 s to T0+1.76 s is best fit by a Band function with Epeak = 89.8 +/- 3.7 keV, alpha = -0.41 +/- 0.07, and beta = -2.4 +/- 0.1 The event fluence (10-1000 keV) in this time interval is (4.8 +/- 0.1)E-06 erg/cm^2. The 1.024-sec peak photon flux measured starting from T0 s in the 10-1000 keV band is 39.06 +/- 0.42 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/"