Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 28747

GRB 201020A: GROWTH-India Telescope late-time optical upper limit
2020-10-22T15:21:06Z (4 years ago)
Harsh Kumar at Indian Inst of Tech,Bombay <>
H. Kumar (IITB), J. Stanzin (IAO), V. Bhalerao(IITB), G. C. Anupama (IIA),
S. Barway (IIA), report on behalf of the GROWTH-India collaboration:

We observed GRB 201020A reported by Swift-BAT (E. Ambrosi et al., GCN
#28696) with 0.7m GROWTH-India telescope. The field was observed in the
SDSS r��� filter with multiple 300-sec exposures. We obtained the following
late time upper limit:

 JD (mean)| T-T0(hrs) | Filter | Exposure (sec) | Lim_mag (5-sigma) |


2459144.094375 | 32.47 | r��� | 14 * 300 (stacked) | > 21.47 |


This upper limit is consistent with our best-fit power-law decay from H.
Kumar et al., GCN #28711. Magnitudes are in the AB system and calibrated
against PanSTARRs PS1 data release, (Flewelling et al., 2018).

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 ( It is located at the
Indian Astronomical Observatory (Hanle), operated by the Indian Institute
of Astrophysics (IIA).
Looking for U.S. government information and services? Visit