TITLE: GCN CIRCULAR NUMBER: 27993 SUBJECT: GRB 200619A: Fermi GBM observation DATE: 20/06/19 21:15:01 GMT FROM: Cori Fletcher at USRA C. Fletcher (USRA) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 02:36:11.67 UT on 19 June 2020, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 200619A (trigger 614226976 / 200619108). This burst was also detected by the AGILE satellite (A. Ursi et al. 2020, GCN 27991) and Insight-HXMT/HE (S. Xiao et al. 2020, GCN 27985). The on-ground calculated location, using the GBM trigger data, is RA = 101.4, DEC = 56.7 (J2000 degrees, equivalent to 06h 45m, 56d 44'), with a statistical uncertainty of 4.0 degrees (radius, 1-sigma containment, statistical only; there is additionally a systematic error which we have characterized as a core-plus-tail model, with 90% of GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg systematic error. [Connaughton et al. 2015, ApJS, 216, 32] ). The angle from the Fermi LAT boresight at the GBM trigger time is 103 degrees. The GBM light curve consists of a single bright peak with a duration (T90) of about 29 s (50-300 keV). The time-averaged spectrum from T0+0.003 s to T0+29.120 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.82 +/- 0.06 and the cutoff energy, parameterized as Epeak, is 1268 +/- 199 keV. The event fluence (10-1000 keV) in this time interval is (1.42 +/- 0.04)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+0.064 s in the 10-1000 keV band is 4.8 +/- 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/"