TITLE: GCN CIRCULAR NUMBER: 8213 SUBJECT: GRB 080905C: Fermi GBM detection DATE: 08/09/11 15:08:30 GMT FROM: Elisabetta Bissaldi at MPE E. Bissaldi, S. McBreen and A. von Kienlin (MPE) report on behalf of the Fermi GBM Team: "At 13:41:29 UT on 5 September 2008, the Fermi Gamma-ray Burst Monitor triggered and located GRB 080905C (trigger 242314890 / 080905570). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 96.9, Dec = -69.8 (J2000 degrees) (equivalent to J2000 06h 28m, -69d 48'), with a statistical uncertainty of 8 degrees (radius, 1-sigma containment; there is additionally a systematic error which is currently estimated to be 2 to 3 degrees). The angle from the Fermi LAT boresight is 108 degrees. This event comprises three pulses beginning at T0-4 s. The main emission occurs during the first 11 sec and T90 (50-300 keV) is about 28 s. The time-averaged spectrum from T0-3.6 s to T0+17 s is adequately fit by a power law function with an exponential high energy cutoff. The power law index is -0.90 +/-0.17 and the cutoff energy, parameterized as Epeak, is 78.8 +/- 5.9 keV. The fluence (25-1000 keV) is 4.6 (+/-0.3)E-06 erg/cm2 and the peak flux (25-1000 keV) on the 128 ms timescale is 4.4 +/- 1.9 ph/cm2/s. The spectral analysis results presented above are preliminary; the final results will be published in the Fermi GBM GRB Catalog."