TITLE: GCN CIRCULAR NUMBER: 33182 SUBJECT: GRB 230116D: GIT optical follow-up DATE: 23/01/17 05:03:49 GMT FROM: Varun Bhalerao at Indian Inst of Tech V. Swain (IITB), H. Kumar (IITB), K. Angail (IAO), V. Bhalerao (IITB), G. C. Anupama(IIA), S. Barway (IIA) report on behalf of the GIT team: [The previous GCN was garbled up, re-posting] We observed GRB 230116D detected by Swift-BAT (Sonbas et al., GCN 33176) and optical afterglow discovered by Z.P. Zhu et al.(GCN 33177), with 0.7m GROWTH-India Telescope (GIT). We started the observation at 21:39:00 UT on 2023-01-16, i.e., 34.28 min after the Swift/BAT trigger and took multiple exposures in the g’, r' and i’ filters. We clearly detected the afterglow in our stacked image at R.A.= 06:34:28.13, DEC.=+49:52:20.6, within the 2.3 arcsec radius circle (J.P. Osborne et al., GCN 33180). The photometric results follow as: ------------------------------------------------------------------- JD (mid) | T_mid-T0(hrs) | Exposure (sec) | Filter | Magnitude (AB) | ------------------------------------------------------------------- 2459961.40208328 | 0.57 | 1 x 20 | r' | >17.63 | 2459961.41763334 | 0.94 | 8 x 300 (stacked) | g’ | 21.04 +/- 0.07 | 2459961.44794164 | 1.67 | 8 x 300 (stacked) | r’ | 19.99 +/- 0.05 | 2459961.47255148 | 2.26 | 5 x 300 (stacked) | i’ | >19.84 | ------------------------------------------------------------------- The results are consistent with S. Nazarov et al.(GCN #33178) and A. S. Moskvitin et al.(GCN #33179).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/.