GCN Circular 25938
E. Bissaldi (Politecnico & INFN Bari), R. Hamburg (UAH) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 06:41:50.58 UT on 1 October 2019, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 191001A (trigger 591604915 / 191001279). The on-ground calculated location has been reported in GCN #25893, and an IPN annulus consistent with the GBM localization was reported in GCN #25926. The ATLAS and DDOTI (GCN #25911) optical counterpart position are consistent with the GBM localization. The GBM light curve consists of several pulses with a duration (T90) of about 24 s (50-300 keV). The time-averaged spectrum from T0-4.99 s to T0+25.73 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.8 +/- 0.1 and the cutoff energy, parameterized as Epeak, is 114 +/- 9 keV. The event fluence (10-1000 keV) in this time interval is (4.7 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+15.7 s in the 10-1000 keV band is 10.5 +/- 0.4 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"