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GCN Circular 27800

GRB 200524A: GROWTH-India confirmation of optical afterglow
2020-05-24T19:58:19Z (4 years ago)
Harsh Kumar at Indian Inst of Tech,Bombay <>
H. Kumar, V. Bhalerao(IITB), G. C. Anupama, S. Barway, U. Stanzin (IIA)
report on behalf of the GROWTH-India collaboration:

We followed up GRB 200524A (F. F. Dirirsa et al., GCN 27797, A. Ho et al.,
GCN 27799) with 0.7m GROWTH-India telescope. We obtained 600-sec exposures
in SDSS g, r, i filters starting at UT 2020-05-24T10:41:57 (~5.6 hrs after
the burst). We detect a faint transient with magnitudes r = 20.56 +- 0.14
and i = 20.59 +- 0.28 (calibrated against PanSTARRs PS1 data release,
et al., 2018). The source position matches with the likely afterglow
candidate by A. Ho et al. (GCN 27799). The fading rate is approximately 3
magnitudes in four hours, consistent with the fading rate reported in the
ZTF GCN. We hereby, confirm ZTF20abbiixp as the afterglow of GRB 200524A.

We obtained the following photometric results:-


 JD(Start) | T-T0(hrs) | Filter | Mag |


2458993.946 | 5.64 | g | > 21.01 (5-sigma)

2458993.954 | 5.83 | r | 20.56 +/- 0.14

2458993.962 | 6.02 | i | 20.59 +/- 0.28


Given the fast fading, we encourage the followup of the source. The
magnitudes are not corrected for galactic extinction.

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).

[GCN OPS NOTE(24may20):  Please see Circular 27804 for a correction to this Circular.]
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