TITLE: GCN CIRCULAR NUMBER: 27809 SUBJECT: GRB 200524A: Fermi GBM detection DATE: 20/05/25 00:03:51 GMT FROM: Stephen Lesage at Fermi-GBM Team S. Pookalil (UAH), B. Mailyan (Institute for Basic Science, South Korea), and R. Hamburg (UAH) report on behalf of the Fermi GBM Team: "At 05:04:00.36 UT on 24 May 2020, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 200524A (trigger 611989445 / GBM200524211), which was also detected by the Fermi/LAT (Dirirsa et al. 2020, GCN 27797) The Fermi GBM Final Real-time Localization is consistent with the LAT position. Swift has initiated a ToO observation of this burst (GCN 27798). The angle from the Fermi LAT boresight at the GBM trigger time is 23 degrees. The GBM light curve shows a multi-peaked structure with a duration (T90) of about 38 s (50-300 keV). The time-averaged spectrum from T0-1.5 s to T0+25.1 s is best fit by a Band function with Epeak = 192 +/- 16 keV, alpha = -0.66 +/- 0.06, and beta = -1.77 +/- 0.03 The event fluence (10-1000 keV) in this time interval is (2.08 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+5.3 s in the 10-1000 keV band is 13.3 +/- 0.3 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/"