GCN Circular 28138

Brajesh Kumar (ARIES, Nainital), Anirban Dutta, Avinash Singh, G. C. 
Anupama, D. K. Sahu and Pramod Kumar (IIA, Bengaluru)

We observed the field of GRB 200716C (Fermi GBM, GCN #28123; Ukwatta et 
al., GCN #28124) with the Himalaya Faint Object Spectrograph and Camera 
(HFOSC) mounted on the 2-m Himalayan Chandra Telescope (IAO, Hanle, 
India). Multiple frames (each 300 sec) of the GRB field in Bessell R and 
I bands were obtained under moderate sky conditions. Preliminary PSF 
photometry on the stacked images was performed and calibrated against 
USNO-B1 catalogue. The estimated magnitudes are listed below:

   DATE     | UT (mean) | Exposure | Filter |  Mag
2020-07-17   17:06:34     300x3        R     17.55 +/- 0.18
2020-07-17   17:23:33     300X3        I     17.19 +/- 0.15

Here, we caution that there is an extended object near the GRB location 
(possibly the host galaxy, D'Avanzo et al. GCN #28132). However, the 
extended source is fainter (~19.23 and ~18.67 mag in R and I bands, 
respectively, USNO-B1). Therefore, the estimated magnitudes likely 
belong to the OT candidate (Lipunov et al., GCN #28125; Hu et al., GCN 
#28126), affected by the host contamination.

We thank the staff at IAO and CREST for helping with the observations.