TITLE:   GCN CIRCULAR
NUMBER:  33198
SUBJECT: GRB 230116D: 3.6m DOT optical upper limit
DATE:    23/01/20 05:06:14 GMT
FROM:    Rahul Gupta at ARIES, India  <rahulbhu.c157@gmail.com>

Rahul Gupta, Amit K. Ror, S. B. Pandey, A. Aryan, S. Pandey, A. Ghosh,
Dimple, and K. Misra (ARIES) report:

We observed the field of GRB 230116D detected by Swift (Sonbas et al., GCN
33176) using the 3.6m Devasthal Optical Telescope of ARIES Nainital. We
have taken multiple frames having an exposure time of 300 sec in the r
filter. We stacked the images after the alignment. We do not detect the
optical afterglow (Zhu et al., GCN 33177; Nazarov et al., GCN 33178;
Moskvitin et al., GCNs 33179, 33187, 33192; Swain et al., GCN 33182; and
Belkin et al., GCNs 33189, 33190, 33191). We obtained the limiting mag of ~
22.7 mag at ~ 1.04 days post-detection.

The limiting magnitudes quoted are not corrected for the Galactic and host
extinction in the direction of the burst. Photometric calibration is
performed using the standard stars from the Pan-STARRS catalog.

This circular may be cited. 3.6m Devasthal Optical Telescope (DOT) is
the recently commissioned facility in the 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.