TITLE: GCN CIRCULAR NUMBER: 8145 SUBJECT: GRB080823: Fermi Gamma-ray Burst Monitor detection DATE: 08/08/27 16:16:58 GMT FROM: Sheila McBreen at MPE S. McBreen , A. von Kienlin and E. Bissaldi (MPE) report on behalf of the Fermi GBM Team: "At 08:42:13 UT on 23 August 2008, the Fermi GBM triggered and located GRB 080823 (trigger 241173734 / 080823.363). The on-ground calculated location, using the GBM trigger data, is RA = 91.8 , Dec = -40.6 (J2000 degrees, equivalent to 06h 07m, -40d 36'), with an uncertainty of 3.3 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 77 degrees. This event comprises a small pulse at T0-3 sec, a main pulse with substructure from 0 to 20 sec and a weaker pulse from 20 to 40 sec. T90 (50-300 keV) is about 46 sec. The time-averaged spectrum from T0 to T0+18s is best fit by a power law function with an exponential high energy cutoff. The cutoff energy, parameterized as Epeak, is 164.7+/-34.2 keV and the power law index is -1.2 +/-0.2. The fluence (50-300 keV) over T90 is 4.1e-6 erg/cm^2. The spectral analysis results presented above are preliminary; the final results will be published in the GBM GRB Catalog."