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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).
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