TITLE: GCN CIRCULAR NUMBER: 22176 SUBJECT: GRB 171126A: AstroSat CZTI detection DATE: 17/12/02 19:48:44 GMT FROM: Vidushi Sharma at IUCAA V. Sharma (IUCAA), V. Bhalerao (IIT-B), D. Bhattacharya (IUCAA), 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 GRB 171126A, which was also detected by Fermi-GBM (Hui C.M. et al., GCN 22170). The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with strongest peak at 05:38:43.810 UT. The measured peak count rate is 530.2 cts/s above the background in combined data of four quadrants, with a total of 2675 cts. The local mean background count rate was 399.8 cts/s. Using cumulative rates, we measure a T90 of 1.1 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.