TITLE: GCN CIRCULAR NUMBER: 30304 SUBJECT: GRB 210619B: SPI-ACS/INTEGRAL observations DATE: 21/06/22 16:17:53 GMT FROM: Alexei Pozanenko at IKI, Moscow P. Minaev, A. Pozanenko, I. Chelovekov, S. Grebenev (IKI) report on behalf of IKI GRB FuN: We report observations of GRB 210619B with the INTEGRAL/SPI-ACS detector (publicly available data). The burst was previously detected in several X-/gamma-ray experiments (D'Avanzo et al., GCN 30261; Axelsson et al., GCN 30270; Poolakkil et al., GCN 30279; Levin et al., GCN 30283; Kawakubo et al., GCN 30284). GRB 210619B was detected by SPI-ACS at (UTC) 2021-06-19T23:59:25. Its duration in the SPI-ACS energy band (> 80 keV) is T_90 = 50.9 ± 0.1 s. Comparing the fluxes measured from a number of long-duration GRBs simultaneously recorded by SPI-ACS and Fermi/GBM (Chelovekov et al., in preparation) we estimated the GRB 210619B fluence to be 1.7e-4 erg/cm^2 in the 10-1000 keV band (the 95% confidence region which includes systematics was 4.9e-5 - 5.9e-4 erg/cm^2). We did not detect any precursor with durations of 0.1 - 5 s during 500 s prior to the trigger time. Also we did not detect any signature of an extended emission up to 1000 s after the trigger time. The SPI-ACS light curve of GRB 210619B can be found at http://grb.rssi.ru/GRB210619B/GRB210619B_SPI-ACS_LC.png