TITLE: GCN CIRCULAR NUMBER: 23827 SUBJECT: GRB 190131A: AstroSat CZTI detection DATE: 19/02/01 13:39:46 GMT FROM: Tanazza Khanam at IUCAA T. Khanam, 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 190131A. 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 23:08:38.5 UT. The measured peak count rate is 216 cts/s above the background in the combined data of four quadrants, with a total of 2804 cts. The local mean background count rate was 518 cts/s. Using cumulative rates, we measure a T90 of 17.6 s. It was also 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.