TITLE: GCN CIRCULAR NUMBER: 31857 SUBJECT: GRB 220408A: GIT optical upper limit DATE: 22/04/08 19:05:42 GMT FROM: Harsh Kumar at Indian Inst of Tech,Bombay H. Kumar (IITB), V. Swain (IITB), R. Norbu (IAO), V. Bhalerao (IITB), G. C. Anupama (IIA), S. Barway (IIA) report on behalf of the GIT team: We observed GRB 220408A detected by Fermi-GBM (GCN #31847) and Swift-BAT (R. Caputo et al., GCN #31848) with 0.7m GROWTH-India Telescope (GIT). We obtained multiple 300-sec exposures in the r' filter and did not detect the afterglow in our stacked images. The obtained upper limits follow as: --------------------------------------------------------------------------------- JD (mid) | T_mid-T0(hrs) | Exposure (sec) | Filter | Lim_mag (5-sigma) | --------------------------------------------------------------------------------- 2459678.21683 | 11.43 | 3000(stacked) | r' | > 21.94 --------------------------------------------------------------------------------- The magnitudes are calibrated against PanSTARRS DR1 (Chambers et al., 2016) and not corrected for Galactic extinction. The GROWTH India Telescope (GIT) 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 operations of the telescope. Telescope technical details are available at https://sites.google.com/view/growthindia/.