GCN Circular 24705
P. Veres and C. Meegan (both UAH) report on behalf of the Fermi GBM Team: "At 20:10:12.14 UT on 31 May 2019, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 190531B (trigger 581026217 / 190531840, GCN #24695), which was also detected by Fermi-LAT (GCN # 24701). The GBM light curve consists of multiple peaks with a duration (T90) of about 38.4 s (50-300 keV). The time-averaged spectrum from T0 to T0+44.4 s is best fit by a Band function with Epeak = 473 +/- 14 keV, alpha = -0.79 +/- 0.01, and beta = -2.33 +/- 0.06. The event fluence (10-1000 keV) in this time interval is (9.91 +/- 0.08)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+31.2 s in the 10-1000 keV band is 27.7 +/- 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/"