TITLE: GCN CIRCULAR NUMBER: 23866 SUBJECT: GRB 190203A: AstroSat CZTI detection DATE: 19/02/04 18:38:24 GMT FROM: Vidushi Sharma at IUCAA T. Khanam, 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 190203A, which was also detected by Swift (Lien A. Y. et al., GCN Circ 23845) and Konus-Wind (Frederiks D. et al., GCN Circ 23859). The source was clearly detected in the 20-200 keV energy range. The light curve shows multiple peaks of emission with the strongest peak at 15:44:14.0 UT. The measured peak count rate is 314 cts/s above the background in the combined data of four quadrants, with a total of 387 cts. The local mean background count rate was 340 cts/s. Using cumulative rates, we measure a T90 of 46.45 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.