[vsnet-grb-info 26676] GRB 201020B: HCT and GIT continued optical follow-up observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  28776
SUBJECT: GRB 201020B: HCT and GIT continued optical follow-up observations
DATE:    20/10/25 09:04:20 GMT
FROM:    Harsh Kumar at Indian Inst of Tech,Bombay  <harshkosli13 at gmail.com>

H. Kumar(IITB), S. Kiran (IIA), J.Stanzin (IAO), V. Bhalerao(IITB), G. C.
Anupama(IIA), S. Barway(IIA) report on behalf of the HCT team:

We followed-up GRB 201020B reported by Fermi GBM Team (GCN #28702, also
see: V. Lipunov et. al., GCN #28718; D. Xu et. al., GCN #28719) with 2.0m
Himalayan Chandra Telescope (HCT) and 0.7m GROWTH-India Telescope (GIT). We
obtained a series of 300-sec exposures in the Rc, r filters. Afterglow was
clearly detected at a position consistent with V. Lipunov et. al., GCN
#28718; D. Xu et. al., GCN #28719. Here are the photometric results from
HCT & GIT observations:-

-------------------------------------------------------

 JD (mid) | T_mid-T0(hrs) | Filter | Mag | Telescope |

-------------------------------------------------------

 2459145.40625 | 52.22 | r | 21.01 +/- 0.04 | GIT |

 2459146.32699 | 74.80 | Rc | 21.28 +/- 0.04 | HCT |

-------------------------------------------------------

Our results are consistent with the power-law decay of 1.67 reported in S.
Belkin et al. GCN #28768; H. Kumar et al. GCN #28753.


These observations were carried out under the ToO program HCT-2020-C3-P6.
We thank HCT and GIT staff for undertaking the observations.

The GROWTH India Telescope (GIT) is a 70-cm telescope with a 0.7 degree
field of view, set up by the Indian Institute of Astrophysics and the
Indian Institute of Technology Bombay with support from the Indo-US Science
and Technology Forum (IUSSTF) and the Science and Engineering Research
Board (SERB) of the Department of Science and Technology (DST), Government
of India (https://sites.google.com/view/growthindia/). It is located at the
Indian Astronomical Observatory (Hanle), operated by the Indian Institute
of Astrophysics (IIA).