TITLE: GCN CIRCULAR NUMBER: 11124 SUBJECT: GRB 100816A: Fermi GBM observation DATE: 10/08/17 19:42:54 GMT FROM: Michael Burgess at UAH G. Fitzpatrick (UCD) reports on behalf of the Fermi GBM Team: "At 00:37:50.94 UT on 16th August 2010, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 100816A (trigger 303611872 / 100816026), which was also detected by the SWIFT-BAT (Oates et al. 2010, GCN 11102) The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight is 82 degrees. The GBM light curve shows a single pulse with a duration (T90) of about 2 s (50-300 keV). The time-averaged spectrum from T0 to T0+ 2.496 s is best fit by a Band function with Epeak = 136.70 +/- 4.73 keV, alpha = -0.31 +/- 0.05, and beta = -2.77 +/- 0.17 (Castor C-STAT 555.02 for 484 d.o.f.). The event fluence (10-1000 keV) in this time interval is (9.10 +/- 0.13) E-06 erg/cm^2. The 1.024-sec peak photon flux measured starting from T0+ 0.38 s in the 10-1000 keV band is 15.59 +/- 0.25 ph/s/cm^2. A power law function with an exponential high energy cutoff fits the spectrum equally well (Castor C-STAT 564.38 for 485 d.o.f.) The cutoff energy, parameterized as Epeak, is 146.30 +/- 3.44 keV and the power law index is -0.38 +/- 0.04. The spectral and temporal analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."