GCN Circular 15573
V. Pelassa and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 03:54:10.43 UT on 26 November 2013, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 131126A (trigger 407130853 / 131126163) which was also detected by Konus/Wind (Golenetskii et al 2013, GCN 15551) leading to an IPN Konus/GBM annulus (Golenetskii et al 2013, GCN 15550). The angle from the Fermi LAT boresight is 108 degrees. iPTF also performed a tiled observation of the localization error box and established an upper limit on the GRB afterglow (Singer et al 2013, GCN 15572). The GBM light curve consists of a single pulse with a duration (T90) of about 0.3 s (50-300 keV). The time-averaged spectrum from T0-0.064 s to T0+0.256 s is adequately fit by a power law function with an exponential high-energy cutoff. The power law index is -0.06 +/- 0.13 and the cutoff energy, parameterized as Epeak, is 600 +/- 62 keV (Castor statistics 397.51 for 364 d.o.f.). A Band function fits the spectrum equally well (Castor statistics 391.35 for 363 d.o.f.) with Epeak= 489 +/- 74 keV, alpha = 0.13 +/- 0.20 and beta = -2.29 +/- 0.26. The event fluence (10-1000 keV) in this time interval is (2.0 +/- 0.1)E-06 erg/cm^2. The 64-msec peak photon flux measured starting from T0+0.000 s in the 10-1000 keV band is 36 +/- 2 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."