TITLE: GCN CIRCULAR NUMBER: 24042 SUBJECT: GRB 190326B: AstroSat CZTI detection DATE: 19/04/02 17:13:12 GMT FROM: Vidushi Sharma at IUCAA V. Sharma, D. Bhattacharya, A. Vibhute and T. Khanam (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 bright GRB 190326B, which was also detected by Fermi-GBM (Kienlin A. von et al., GCN # 24013) and Insight-HXMT/HE detection (Luo Q. et al., GCN # 24019). The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple pulses of emission with strongest peak at 07:32:36.5 UT. The measured peak count rate associated with the burst is 418 cts/s above the background in the combined data of four quadrants, with a total of 4932 cts. The local mean background count rate was 630 cts/s. Using cumulative rates, we measure a T90 of 54.3 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.