TITLE: GCN CIRCULAR NUMBER: 25254 SUBJECT: GRB 190720B: AstroSat CZTI detection DATE: 19/08/02 11:25:01 GMT FROM: Prachee Ghumatkar at IUCAA/AstroSat P. Ghumatkar, V. Sharma and D. Bhattacharya (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 190720B, which was also detected by Fermi GBM (GCN #25132) and Insight-HXMT/HE (Luo Q. et. al., GCN #25137). The source was clearly detected in the 40-200 keV energy range. The light curve shows single pulse of emission with strongest peak at 23:08:40.0 UT. The measured peak count rate associated with the burst is 116 cts/s above the background in the combined data of four quadrants, with a total of 493 cts. The local mean background count rate was 507 cts/s. Using cumulative rates, we measure a T90 of 8.5 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.