TITLE: GCN CIRCULAR NUMBER: 31104 SUBJECT: GRB 211120A: AstroSat CZTI detection DATE: 21/11/23 05:52:20 GMT FROM: Gaurav Waratkar at IIT,Bombay V. Prasad (IUCAA), P. Sawant (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration: Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed detection of a long GRB 211120A, which was also detected by GECAM (Li et al., GCN 31100). The source was clearly detected in the 20-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2021-11-20 23:05:22.85 UT. The measured peak count rate associated with the burst is 1756 (+251, -174) cts/s above the background in the combined data of two quadrants, with a total of 2263 (+183, -134) cts. The local mean background count rate was 443 (+4, -8) cts/s. Using cumulative rates, we measure a T90 of 4.8 (+0.6, -0.2) 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 [1]. 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. Links: ------ [1] http://astrosat.iucaa.in/czti/?q=grb