TITLE: GCN CIRCULAR NUMBER: 26378 SUBJECT: GRB191102A: AstroSat CZTI discovery of a burst DATE: 19/12/07 06:56:21 GMT FROM: Varun Bhalerao at Indian Inst of Tech V. Shenoy (IITB), Y. Sharma (Caltech), V. Bhalerao (IITB), D. Bhattacharya (IUCAA), A. R. Rao (TIFR), S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration: Analysis of AstroSat CZTI data showed detection of a GRB 191102A. The source was detected in the 40-200 keV energy range. The light curve showed single pulse of emission peaking at 2019-11-02 12:18:21 UT. The measured peak count rate associated with the burst is 198 cts/s above the background in the combined data of four quadrants, with a total of 634 cts. The local mean background count rate was 573 cts/s. Using cumulative rates, we measure a T90 of 4.4 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.