GCN Circular 42334
Subject
GRB 251013C: Liverpool Telescope observations
Event
Date
2025-10-17T21:03:54Z (13 hours 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 field of GRB 251013C (Fermi GBM team, GCN 42221; Rakotondrainibe et al., GCN 42222) using the IO:O optical camera on the 2m robotic Liverpool Telescope. We obtained 60s exposures in the SDSS ugriz filters, starting on 2025-10-14 01:46:49, about 8.1h after Fermi trigger.
We report detections in all bands, at the position of the optical afterglow first reported by Palmerio et al., GCN 42223:
MJD (start) T_mid-T_0 Filter Mag. (AB)
60962.07711 8.20 h u 19.07 ± 0.10
60962.07418 8.13 h g 18.62 ± 0.04
60962.07517 8.15 h r 18.36 ± 0.02
60962.07614 8.17 h i 18.14 ± 0.03
60962.07877 8.24 h z 18.00 ± 0.03
The photometry for griz filters was calibrated using nearby PanSTARRS secondary standards, while u-band photometry was calibrated using the SDSS catalogue. The photometry is not corrected for extinction.