TITLE: GCN CIRCULAR NUMBER: 28686 SUBJECT: GRB 201013A: 3.6m DOT Optical Observations DATE: 20/10/19 14:42:24 GMT FROM: Rahul Gupta at ARIES, India R. Gupta (ARIES), A. Kumar (ARIES), Dimple (ARIES), A. Ghosh (ARIES), A. Aryan (ARIES), B. Kumar (ARIES), S. B. Pandey (ARIES), and K. Misra (ARIES) report: We observed the XRT localized GRB 201013A detected by Swift-BAT (Beardmore et al., GCN 28608, Page et al., GCN 28607; see also: Laha et al., GCN 28614; Tamura et al., GCN 28618; Gupta et al., GCN 28620; Zheng et al., GCN 28625; Tsvetkova et al., GCN 28652) using the 4Kx4K CCD Imager (Pandey et al. 2018, 2018BSRSL..87...42P) mounted at the axial port of the 3.6m Devasthal Optical Telescope of ARIES Nainital on 13 th and 14 th October 2020. Multiple frames having exposure times of 300s each were taken in B and R filters. The measured magnitudes of the bright optical object (USNO-B1.0 1470-0207304) present within the XRT error circle (Beardmore et al., GCN 28608) are consistent with those reported in the USNO-B1.0 catalog (Rmag2=16.22, Bmag2= 16.49) in both the filters. We do not find any evidence of an afterglow candidate in the close vicinity. We obtain the following 3-sigma upper limits. Date UT start T-T0 Exp. Filter OT Err. UL Telescope (days) 2020-10-13 22:01:55 0.7607 3*300 R NA NA 23.2 3.6m DOT 2020-10-13 22:18:14 0.7720 3*300 B NA NA 23.5 3.6m DOT The limiting magnitudes quoted are not corrected for the Galactic and Host extinction in the direction of the burst. 3.6m Devasthal Optical Telescope (DOT) is a recently commissioned facility in Northern Himalayan region of India (long:79 41 04E, lat:29 21 40N, alt:2540m) owned and operated by the Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital (https://www.aries.res.in). Authors of this GCN circular thankfully acknowledge consistent support from the staff members to run and maintain the 3.6m DOT. This circular may be cited.