TITLE: GCN CIRCULAR NUMBER: 8494 SUBJECT: GRB 081107: Fermi GBM detection DATE: 08/11/07 15:51:17 GMT FROM: Andreas von Kienlin at MPE A. von Kienlin (MPE) and E. Bissaldi (MPE) report on behalf of the Fermi GBM Team: "At 07:42:01.11 UT on 07 November 2008, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 081107 (trigger 247736522 / 081107321). The on-ground calculated location, using the GBM trigger data, is RA = 47.7, DEC = +17.0 (J2000 degrees, equivalent to 03h 11m, 17d 00'), with an uncertainty of 4.3 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 52 degrees. The GBM light curve shows one major structured peak with a duration (T90) of about 2.2 s (8-1000 keV). The time-averaged spectrum from T0-0.201 s to T0+1.655 s is best fit by a Band function with Epeak = 65 +/- 3 keV, alpha = 0.25 +/- 0.17, and beta = -2.80 +/- 0.15 (chi squared 542 for 481 d.o.f.). The event fluence (8-1000 keV) in this time interval is (1.64 +/- 0.28)E-06 erg/cm^2. The 1-sec photon flux measured starting from T0-0.073 s in the 8-1000 keV band is 11 +/- 3 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."