GCN Circular 31857
Subject
GRB 220408A: GIT optical upper limit
Date
2022-04-08T19:05:42Z (3 years ago)
From
Harsh Kumar at Indian Inst of Tech,Bombay <harshkosli13@gmail.com>
H. Kumar (IITB), V. Swain (IITB), R. Norbu (IAO), V. Bhalerao (IITB), G. C.
Anupama (IIA), S. Barway (IIA) report on behalf of the GIT team:
We observed GRB 220408A detected by Fermi-GBM (GCN #31847) and Swift-BAT
(R. Caputo et al., GCN #31848) with 0.7m GROWTH-India Telescope (GIT). We
obtained multiple 300-sec exposures in the r' filter and did not detect the
afterglow in our stacked images. The obtained upper limits follow as:
---------------------------------------------------------------------------------
JD (mid) | T_mid-T0(hrs) | Exposure (sec) | Filter | Lim_mag (5-sigma) |
---------------------------------------------------------------------------------
2459678.21683 | 11.43 | 3000(stacked) | r' | > 21.94
---------------------------------------------------------------------------------
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 https://sites.google.com/view/growthindia/.