TITLE: GCN CIRCULAR NUMBER: 30402 SUBJECT: GRB 210706A: GIT optical upper limits DATE: 21/07/07 12:39:54 GMT FROM: Harsh Kumar at Indian Inst of Tech,Bombay H. Kumar (IITB), R. Norbu (IAO), V. Bhalerao (IITB), G. C. Anupama (IIA), S. Barway (IIA) report on behalf of the GIT team: We observed GRB 210706A detected by Swift/BAT-GUANO (see A. Tohuvavohu et al. GCN #30393) with 0.7m GROWTH-India Telescope (GIT). We obtained multiple 100-second images in g', r' and i' bands, interspersed with each other. The total exposure in each band was 1000 seconds. We did not detect any new source in our stacked images within the 3.2 arcsec circle, around the swift XRT position centered at RA: 20h 47m 58.73s Dec: +13d 19' 01.0" (GCN #30399). Also, we did not detect any new transient within the full 5 arcmin circle around the Swift/BAT-GUANO position (GCN #30393). The obtained upper limit follow as: ------------------------------------------------------------------- JD (mid) | T_mid-T0(hrs) | Filter | Lim_mag (5-sigma) | ------------------------------------------------------------------- 2459402.343657 | 11.95 | g' | > 20.86 | 2459402.346588 | 12.02 | r' | > 21.00 | 2459402.349518 | 12.09 | i' | > 20.32 | ------------------------------------------------------------------- The magnitudes are calibrated against PanSTARRS (Flewelling et al., 2018) 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 and the Indian Institute of Technology Bombay with support from the Indo-US Science and Technology Forum (IUSSTF) and the Science and Engineering Research Board (SERB) of the Department of Science and Technology (DST), Government of India (https://sites.google.com/view/growthindia/). It is located at the Indian Astronomical Observatory (Hanle), operated by the Indian Institute of Astrophysics (IIA).