TITLE: GCN CIRCULAR NUMBER: 34869 SUBJECT: GRB 231020A: Fermi GBM Detection DATE: 23/10/21 15:40:20 GMT FROM: sumanbala2210@gmail.com S. Bala (USRA) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 18:56:58.30 UT on 20 October 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 231020A (trigger 719521023/231020790). The Fermi GBM Final Real-time Localization is reported in GCN 34856. The GBM light curve consists of a single bright peak with a duration (T90) of about 9.3 s (50-300 keV). The time-averaged spectrum from T0-0.5 to T0+21 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.34 +/- 0.01 and the cutoff energy, parameterized as Epeak, is 145 +/- 3 keV. The event fluence (10-1000 keV) in this time interval is (3.81 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+6.6 s in the 10-1000 keV band is 87.2 +/- 0.8 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/" View this GCN Circular online at https://gcn.nasa.gov/circulars/34869. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...