GCN Circular 9844
S. McBreen (UCD/MPE) reports on behalf of the Fermi GBM Team: "At 02:22:48.20 UT on 28 August 2009, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 090828 (trigger 273118970 / 090828099 ). The on-ground calculated location, using the GBM trigger data, is RA = 124.4, DEC = -26.1 (J2000 degrees, equivalent to 08 h 18 m, -26 d 06 '), with an uncertainty of 1.2 degrees (radius, 1-sigma containment, statistical only; there is additionally a systematic error which is currently estimated to be 2 to 3 degrees). The angle from the Fermi LAT boresight is 95 degrees. This burst was also independently detected by INTEGRAL SPI-ACS. The GBM light curve consists of three pulses with a duration (T90) of about 100 s (8-1000 keV). The time-averaged spectrum from T0-0 s to T0+103 s is well fit by a Band function with Epeak = 136.5 (+16.0/-13.7) keV, alpha = -1.23 (+0.06/-0.05), and beta = -2.12 (+0.08/-0.11) (chi squared 549 for 485 d.o.f.). The event fluence (8-1000 keV) in this time interval is (2.52 +/- 0.08)E-5 erg/cm^2. The 1-sec peak photon flux measured starting from T0+52.2 s in the 8-1000 keV band is 16.2 +/- 0.5 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."