GCN Circular 31892
Subject
GRB 220412B: GIT optical upper limit
Date
2022-04-13T08:47:40Z (3 years ago)
From
Harsh Kumar at Indian Inst of Tech,Bombay <harshkosli13@gmail.com>
H. Kumar (IITB), V. Swain (IITB), R. Norbu (IAO), G. C. Anupama (IIA), V.
Bhalerao (IITB), S. Barway (IIA) report on behalf of the GIT team:
We observed the short GRB 220412B detected by Swift-BAT (J.D. Gropp et al.,
GCN #31886) with the 0.7m *GROWTH-India Telescope* (GIT). We obtained multiple
300-sec exposures in the r' filter. We did not detect any new source in our
stacked image within the BAT uncertainty region of 3 arcmin circle, around
R.A.= 320.794, DEC.= -0.223. The obtained upper limit follows as:
-------------------------------------------------------------------------
JD (mid) | T_mid-T0(hrs) | Exposure (sec) | Filter | Lim_mag (5-sigma) |
-------------------------------------------------------------------------
2459682.452891 | 5.75 | 300 x 6 (stacked) | r' | > 20.25 |
-------------------------------------------------------------------------
Our upper limit is consistent with results from K. L. Murata et al. (GCN
#31889). The magnitudes are calibrated against Pan-STARRS 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 https://sites.google.com/view/growthindia/.