TITLE: GCN CIRCULAR NUMBER: 32956 SUBJECT: GRB 221120A: GIT upper limits on optical afterglow DATE: 22/11/21 01:24:33 GMT FROM: Varun Bhalerao at Indian Inst of Tech V. Swain (IITB), H. Kumar (IITB), R. Norboo (IAO), V. Bhalerao (IITB), G. C. Anupama (IIA), S. Barway (IIA) report on behalf of the GIT team: We observed the short GRB 221120A detected by Swift (R. A. J. Eyles-Ferris et al., GCN 32955), with the 0.7m GROWTH-India Telescope (GIT). The observations started at 22:31:28 UT on 2022-11-20, 62 mins after the Swift trigger. We obtained multiple 300-sec exposures in the g', r' and i' filters. We did not detect any new source in our stacked images within the 1.9 arcsec radius circle around R.A.= 02h 45m 21.24s, Dec.= +43d 14' 34.1". The obtained upper limits follow as: ------------------------------------------------------------------- JD (mid) | T_mid-T0(hrs) | Exposure (sec) | Filter | Lim_mag (5-sigma) | ------------------------------------------------------------------- 2459904.44036416 | 1.08 | 3 x 300 (stacked) | g' | > 21.24 | 2459904.46842522 | 1.75 | 8 x 300 (stacked) | r' | > 21.37 | 2459904.46658235 | 1.70 | 3 x 300 (stacked) | i' | > 20.44 | ------------------------------------------------------------------- The magnitudes are calibrated against PanSTARRS DR1 (Chambers et al., 2016) and not corrected for Galactic extinction. The GROWTH India Telescope (GIT; Kumar et al. 2022 >) is a 70-cm telescope with a 0.7-degree field of view, set up by the Indian Institute of Astrophysics (IIA) and the Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and IUSSTF. It is located at the Indian Astronomical Observatory (Hanle), operated by IIA. We acknowledge funding by the IITB alumni batch of 1994, which partially supports the telescope’s operations. Telescope technical details are available at https://sites.google.com/view/growthindia/ .