GCN Circular 40190
Subject
GRB 250419A: Liverpool Telescope observations
Date
2025-04-21T10:19:17Z (3 days ago)
From
A. Bochenek at Liverpool John Moores University <a.m.bochenek@2023.ljmu.ac.uk>
Via
Web form
A. Bochenek and D. A. Perley (LJMU) report:
We observed the SVOM-detected GRB250419a (Wang et al., GCN 40168) using the IO:O optical camera on the 2m robotic Liverpool Telescope. We obtained 6x100s exposures in the SDSS r’ and i’ filters starting at 2025-04-20 21:43:22 UT, approximately 1.80 days after the trigger.
We report a detection in both bands at the position of the optical counterpart (López et al., GCN 40169; Xin et al., GCN 40170; Zheng et al., GCN 40171; Kumar et al., GCN 40172; Thakur et al., GCN 40174; Lipunov et al., GCN 40179; Odeh et al., GCN 40180; Perley et al., GCN 40181; Pankov et al., GCN 40182; Pérez-Fournon GCN 40183; Kuin et al., GCN 40185; WU et al., GCN 40186; Xie et al., GCN 40187, Jiang et al., GCN 40188, Ghosh et al., GCN 40189). The obtained magnitudes are r = 20.61 ± 0.09 and i = 20.41 ± 0.08. The photometry was calibrated using nearby PanSTARRS secondary standards and was not corrected for extinction.
MJD (mid) T_mid-T_0 Filter Mag. (AB)
60785.90925 43.33 h r 20.61 ± 0.09
60785.91782 43.54 h i 20.41 ± 0.08