GCN Circular 28138
Subject
GRB 200716C: Optical observations from HCT
Event
Date
2020-07-18T12:03:42Z (5 years ago)
From
Brajesh Kumar at Indian Inst. of Astrophysics <brajesh.kumar@iiap.res.in>
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.