GCN Circular 10223
D. Tierney (UCD) and S. McBreen (UCD/MPE) report on behalf of the Fermi GBM Team: "At 07:59:24.76 UT on 26 November 2009, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 091126 (trigger 280915166 / 091126333). The on-ground calculated location, using the GBM trigger data, is RA = 83.3, DEC = -19.3 (J2000 degrees, equivalent to 05 h 33 m, -19 d 18 '), with an uncertainty of 5.4 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 93 degrees. This burst was also independently detected by INTEGRAL SPI-ACS. The GBM light curve consists of one pulse with a duration of about 0.3 s (8-1000 keV). The time-averaged spectrum from T0-0.256 s to T0+0.256 s is adequately a power law function with an exponential high energy cutoff. The power law index is -0.60 (+0.24/-0.21) and the cutoff energy, parameterized as Epeak, is 458 (+215/-107) keV (CSTAT 478 for 476 d.o.f.). The event fluence (8-1000 keV) in this time interval is (5.9 +/- 0.5)E-7 erg/cm^2. The 0.128 sec peak photon flux measured starting from T0+0 s in the 8-1000 keV band is 8.3 +/- 0.7 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."