GCN Circular 42844

Subject

GRB 251126A: GIT discovery of the likely optical afterglow

Event

GRB 251126A

Date

2025-11-26T19:41:15Z (a day ago)

Edited On

2025-11-26T21:57:00Z (20 hours ago)

From

V. Swain at IIT Bombay <vishwajeet.s@iitb.ac.in>

Edited By

Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@nasa.gov> on behalf of V. Swain at IIT Bombay <vishwajeet.s@iitb.ac.in>

Via

Web form

V. Swain, T. Mohan, S. Patil, A.P. Saikia, V. Bhalerao (IITB), G.C. Anupama, S. Barway (IIA) and K. Angail (IAO) report on behalf of the GIT team:

We observed the field of GRB 251126A detected by Swift (Caputo et al., GCN 42843

) with 0.7m GROWTH-India Telescope (GIT). We started observations at 2025-11-26T19:14:32 UT, i.e., 3.93 mins after the Swift/BAT trigger. We obtained multiple frames in the r' band of 360 sec each. We detected an uncatalogued source at RA 06:39:46.42, Dec: +54:59:11.78 with an uncertainty of 0.4 arcsec. There is no minor planet present at this position. The photometric results follow as:

JD (mid)	tmid-t0 (mins)	Filter	Exposure (s)	Mag (AB)
2461006.3017592593	3.93	r'	360	18.26 +- 0.06

We encourage photometric for further confirmation and spectroscopic follow-up for redshift measurement. The magnitudes are calibrated against PanSTARRS DR1 (Chambers et al., 2016) and not corrected for Galactic extinction.

The GROWTH India Telescope (GIT; Kumar et al. 2022) 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 the operations of the telescope. Telescope technical details are available at https://sites.google.com/view/growthindia/.