GCN Circular 8793
A. Goldstein (UAH), R. Preece (UAH), and A.J. van der Horst (NASA/ORAU) report on behalf of the Fermi GBM Team: "At 16:20:42.77 UT on 07 January 2009, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 090107B (trigger 25303844 / 090107681). This burst was also detected by the INTEGRAL IBAS (D. Gotz et al. 2009, GCN 8786) The GBM on-ground location is consistent with the INTEGRAL position. The GBM light curve consists of two main emission peaks and apparent substructure with a duration (T90) of about 24.1 s (8-1000 keV). The time-averaged spectrum from T0-4.1 s to T0+20.5 s is best fit by a power law function with an exponential high energy cutoff. The power law index is -0.68 +/- 0.26 and the cutoff energy, parameterized as Epeak, is 106.1 +/- 14.8 keV (chi squared 530.4 for 486 d.o.f.). The event fluence (8-1000 keV) in this time interval is (1.75 +/- 0.37)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+6.1 s in the 8-1000 keV band is 3.68 +/- 0.27 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."