TITLE: GCN CIRCULAR NUMBER: 26201 SUBJECT: GRB 191106A: AstroSat CZTI detection DATE: 19/11/08 12:52:56 GMT FROM: Vidushi Sharma at IUCAA R. Gaikwad, S. Gupta, 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 a weak detection of a GRB 191106A, which was also detected by Swift (Marshall F. E. et al., GCN # 26177), MASTER (Lipunov V. et al., GCN # 26178), BOOTES-4/MET (Hu Y.-D. et al., GCN # 26179), Mondy (Belkin S. et al., GCN # 26180), Swift-XRT (Page K. L. et al., GCN # 26190), NOT (Zhu Z. P. et al., GCN # 26191), Swift/BAT (Barthelmy S. D. et al., GCN # 26198) and Swift/UVOT (Oates S. R. et al., GCN # 26199). The source was detected in the 40-200 keV energy range. The light curve showed single pulse of emission peaking at 2019-11-06 14:15:23.0 UT. The measured peak count rate associated with the burst is 134 cts/s above the background in the combined data of four quadrants, with a total of 408 cts. The local mean background count rate was 502 cts/s. Using cumulative rates, we measure a T90 of 3.6 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.