TITLE: GCN CIRCULAR NUMBER: 26783 SUBJECT: GRB 200111A: AstroSat CZTI detection DATE: 20/01/16 10:01:06 GMT FROM: Ramkrishna Gaikwad at IUCAA/AstroSat 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 the detection of a GRB 200111A, which was also detected by Fermi GBM Final Real-time Localization (GCN #26705) and Insight-HXMT/HE (Xiao S. et al., GCN #26714). The source was clearly detected in the 40-200 keV energy range. The light curve showed multiple peaks of emission peaking at 2020-01-11 15:11:09.0 UT. The measured peak count rate associated with the burst is 421 cts/s above the background in the combined data of four quadrants, with a total of 1251 cts. The local mean background count rate was 548 cts/s. Using cumulative rates, we measure a T90 of 8.6 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.