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GCN Circular 32012

GRB 220506A: GIT optical upper limit.
2022-05-09T19:01:11Z (2 years ago)
Harsh Kumar at Indian Inst of Tech,Bombay <>
V. Swain (IITB), H. Kumar (IITB), K. Angail (IAO), V. Bhalerao (IITB), G.
C. Anupama (IIA), S. Barway (IIA) report on behalf of the GIT team:

We observed GRB 220506A detected by MAXI/GSC (Urabe et al. GCN #32001) and
Swift (Phil Evans et al. GCN #32005), with a 0.7m GROWTH-India Telescope
(GIT). The observation started at 19:08:47 UT on 2022-05-06, 12.68 hours
after the MAXI/GSC trigger. We obtained multiple 300-sec exposures in the
r' filter. We did not detect any new source in our stacked image within the
7.2 arcsec radius circle around R.A.= 15h 58m 54.18s, Dec.= -26d 25' 06.9"
(Phil Evans et al. GCN #32006). The obtained upper limit follows as:
 JD (mid) | T_mid-T0(hrs) | Exposure (sec) | Filter | Lim_mag (5-sigma) |
 2459706.327602595 | 13.39 | 7 x 300 (stacked) | r' | >20.38 |

The magnitudes are calibrated against PanSTARRS DR1 (Chambers et al., 2016)
and 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 (IIA) and the
Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and
IUSSTF. It is located at the Indian Astronomical Observatory (Hanle),
operated by IIA. We acknowledge funding by the IITB alumni batch of 1994,
which partially supports operations of the telescope. Telescope technical
details are available at
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