TITLE: GCN CIRCULAR NUMBER: 23457 SUBJECT: GRB 181126A: Fermi GBM observation DATE: 18/11/26 17:46:16 GMT FROM: Elisabetta Bissaldi at INFN,Bari E. Bissaldi (Politecnico & INFN Bari) reports on behalf of the Fermi GBM Team: "At 09:54:09.94 UT on 26 November 2018, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 181126A (trigger 564918854/ 181126413), which was also detected by the Swift-BAT (Sonbas et al. 2018, GCN 23453). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi-LAT boresight at the GBM trigger time is 111 degrees. The GBM light curve consists of bright single pulse with a duration (T90) of about 0.6 s (50-300 keV). The time-averaged spectrum from T0-0.1 s to T0+0.4 s is adequately fit by a Band function with Epeak = 90 +/- 25 keV, alpha = -0.1 +/- 0.6, and beta = -2.1 +/- 0.2. The event fluence (10-1000 keV) in this time interval is (4.8 +/- 0.5)E-07 erg/cm^2. The 64-ms peak photon flux measured starting from T0-64 ms in the 10-1000 keV band is 10.5 +/- 1.7 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."