TITLE: GCN CIRCULAR NUMBER: 27897 SUBJECT: GRB 200530A: Fermi GBM detection DATE: 20/06/06 23:30:30 GMT FROM: Joshua Wood at MSFC/Fermi-GBM J. Wood (NASA/MSFC) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 00:44:10.57 UT on 30 May 2020, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 200530A (trigger 612492255 / GBM200530031), which was also detected by the Fermi/LAT (Longo et al. 2020, GCN 27891) The Fermi GBM Final Real-time Localization is consistent with the LAT position. The angle from the Fermi LAT boresight at the GBM trigger time is 41 degrees. The GBM light curve shows a multi-peaked structure with a duration (T90) of about 23 s (50-300 keV). The time-averaged spectrum from T0-1.5 s to T0+28.2 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.55 +/- 0.02 and the cutoff energy, parameterized as Epeak, is 178 +/- 4 keV. The event fluence (10-1000 keV) in this time interval is (2.27 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+10.0 s in the 10-1000 keV band is 10.9 +/- 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/"