TITLE: GCN CIRCULAR NUMBER: 32886 SUBJECT: GRB 221028A: HCT optical upper limit DATE: 22/10/29 08:49:36 GMT FROM: Harsh Kumar at Indian Inst of Tech,Bombay H. Kumar (IITB), A. Dutta (IIA), D.K. Sahu (IIA), G. C. Anupama (IIA), S. Barway (IIA), V. Bhalerao (IITB), R. Gupta (ARIES), K. Misra (ARIES), D. Panchal (ARIES), S.B. Pandey (ARIES), report on behalf of the HCT team: We observed GRB 221028A detected by Swift-BAT (A. Y. Lien et al. GCN # 32874) with the 2.0m Himalayan Chandra Telescope (HCT) of the Indian Astronomical Observatory (IAO). We obtained exposures in the Bessel V, Rc and Ic filters and did not detect any afterglow within the Swift-XRT uncertainty circle (A. Y. Lien et al. GCN # 32874). The obtained upper limits follow as: ------------------------------------------------------------------- JD (mid) | T_mid-T0(hrs) | Exposure (sec) | Filter | Lim_mag (5-sigma) | ------------------------------------------------------------------- 2459881.075085 | 0.52 | 60 | Rc | > 19.94 | 2459881.091424 | 0.92 | 300 | Rc | > 22.06 | 2459881.1037215| 1.21 | 300 | Ic | > 20.74 | 2459881.108775 | 1.33 | 420 | V | > 22.30 | ------------------------------------------------------------------- The upper limits are consistent with Kumar et al., GCN #32876; Hu et al., GCN #32878; Lipunov et al., GCN #32879, R. Strausbaugh et al., GCN #32881. The reported magnitudes are in the AB system of magnitude, calibrated against PanSTARRS DR1 (Chambers et al., 2016) using Lupton's transformation equations available at http://classic.sdss.org/dr4/algorithms/sdssUBVRITransform.html#Lupton2005 and not corrected for Galactic extinction. These observations were carried out under the ToO program HCT-2022-C3-P12. We thank the HCT staff for their support during the observations. The Indian Astronomical Observatory is operated by the Indian Institute of Astrophysics, Bengaluru, India.