TITLE: GCN CIRCULAR NUMBER: 24883 SUBJECT: GRB 190619B: AstroSat CZTI detection DATE: 19/06/26 06:22:17 GMT FROM: Prachee Ghumatkar at IUCAA/AstroSat P. Ghumatkar, V. Sharma, D. Bhattacharya and A. Vibhute (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration: Analysis of AstroSat CZTI data showed the detection of a long GRB 190619B, which was also detected by Fermi GBM (GCN #24851), BALROG (Burgess J. et la., GCN #24852) and Global MASTER-Net (Lipunov V. et al., GCN #24853). The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple pulses of emission with strongest peak at 14:16:44.5 UT. The measured peak count rate associated with the burst is 251 cts/s above the background in the combined data of four quadrants, with a total of 3318 cts. The local mean background count rate was 620 cts/s. Using cumulative rates, we measure a T90 of 38.6 s. It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.