TITLE: GCN CIRCULAR NUMBER: 33874 SUBJECT: GRB 230524A: Fermi GBM Observation DATE: 23/05/25 10:00:14 GMT FROM: Andreas von Kienlin at MPE A. von Kienlin (MPE) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 06:06:35 UT on 24 May 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230524A (trigger 706601200/230524255), which was also detected by AGILE (Panebianco et al. 2023, GCN 33867) and AstroSAT/CZTI (Navaneeth et al. 2022, GCN 33868). The Fermi GBM Final Real-time Localization was reported in GCN 33864. The GBM light curve consists of a single emission with a duration (T90) of about 35 s (50-300 keV). The time-averaged spectrum from T0-2.0 to T0+36.9 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.99 +/- 0.04 and the cutoff energy, parameterized as Epeak, is 1632 +/- 415 keV. The event fluence (10-1000 keV) in this time interval is (1.58 +/- 0.05)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0-2 s in the 10-1000 keV band is 2.7 +/- 0.2 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/"