TITLE: GCN CIRCULAR NUMBER: 15382 SUBJECT: GRB 131024B: Fermi GBM observation DATE: 13/10/25 16:48:55 GMT FROM: Binbin Zhang at UAH Bin-Bin Zhang (UAH) reports on behalf of the Fermi GBM Team: "At 21:35:28.85 UT on October 24 2013, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 131024B (trigger 404343331/131024900), which was also detected by Swift (Krimm et al., GCN 15371). The GBM on-ground location is consistent with the Swift/XRT position (Beardmore et al., GCN 15374). The angle from the Fermi LAT boresight is 83 degrees. The GBM light curve consists of a multiple-peak structure with a duration of about 52 s (50-300 keV). The time-averaged spectrum from T0+0 s to T0+41 s is well best fit with a power law function with an exponential high-energy cutoff parameterized as Epeak = 1047 +/- 627 keV and an Index = -1.01 +/- 0.12. The event fluence (10-1000 keV) in this time interval is (6.35 +/- 0.61)E-06 erg/cm^2. The 1.0-sec peak photon flux measured starting from T0+1 s in the 10-1000 keV band is 1.48 +/- 0.2 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."