GCN Circular 37372
Subject
GRB 240825A: MeerLICHT afterglow detection
Date
2024-09-02T08:12:26Z (4 months ago)
From
Simon de Wet at University of Cape Town <simdewet@gmail.com>
Via
Web form
S. de Wet (UCT), P.M. Vreeswijk (Radboud) and P.J. Groot (Radboud/UCT/SAAO) report on behalf of the MeerLICHT consortium:
The 0.6 m wide-field MeerLICHT optical telescope located in Sutherland, South Africa, obtained a repeated series of 60 s exposures in the q,u,g,r,i,z bands of GRB 240825A following the Swift detection (Gupta et al., GCN 37274). Observations started at 20:55:58 UT on 2024 August 25 (5.03 hours post-trigger) and continued for a further 5.87 hours, following the filter sequence quqgqrqiqz.
Since the afterglow was near our single-exposure detection limit due to poor seeing conditions, we coadded multiple exposures in each filter in order to obtain deeper images. We detect the optical afterglow at the UVOT position with the following AB magnitudes at a mean time of 01:03:03 UT on 2024 August 26:
g = 20.68 +/- 0.23
q = 20.81 +/- 0.20
i = 20.24 +/- 0.36
MeerLICHT is built and run by a consortium consisting of Radboud University, University of Cape Town, the South African Astronomical Observatory, the University of Oxford, the University of Manchester and the University of Amsterdam.