GCN Circular 19835
M. Stanbro (UAH) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 20:34:30.04 UT on 21 August 2016, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 160821A (trigger 493504474 / 160821857), which was also detected by the Swift/BAT (Siegel et al. 2016, GCN 19830) and by the LAT (McEnery et al. 2016, GCN 19831). The GBM on-ground location is consistent with the Swift position. The GBM light curve shows/consists of several episodes and a bright burst with a duration (T90) of about 43 s (50-300 keV). The time-averaged spectrum from T0-4.1 s to T0+194.6 s is best fit by a Band function with Epeak = 968 +/- 16 keV, alpha = -1.08 +/- 0.00, and beta = -2.38 +/- 0.03 The event fluence (10-1000 keV) in this time interval is (550.3 +/- 1.39)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+135.7 s in the 10-1000 keV band is 123.1 +/- 0.7 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."