GCN Circular 15396
A. von Kienlin (MPE) reports on behalf of the Fermi GBM Team: "At 01:49:02.35 UT on 28 October 2013, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 131028A (trigger 404617745 / 131028076). The on-ground calculated location, using the GBM trigger data, is RA = 57.0, DEC = +72.2 (J2000 degrees, equivalent to 03 h 48 m, 72 d 12 '), 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 123 degrees. This burst was also independently detected by INTEGRAL SPI-ACS. The GBM light curve consists of a single pulse with a duration (T90) of about 17 s (50-300 keV). The time-averaged spectrum from T0-1.28 s to T0+22.27 s is best fit by a Band function with Epeak = 888 +/-18 keV, alpha = -0.71 +/- 0.01, and beta = -3.4 +/-0.2. The event fluence (10-1000 keV) in this time interval is (1.62 +/- 0.02)E-04 erg/cm^2. The 1.024-sec peak photon flux measured starting from T0+8.13 s in the 10-1000 keV band is 62 +/- 1 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."