TITLE: GCN CIRCULAR NUMBER: 42977 SUBJECT: GRB 251202A / EP251202a: Liverpool Telescope optical follow-up observations DATE: 25/12/03 20:41:04 GMT FROM: A. Bochenek at Liverpool John Moores University a.m.bochenek@2023.ljmu.ac.uk

A. Bochenek, D. A. Perley (LJMU) and A. Y. Q. Ho (Cornell) report:

We observed the field of GRB 251202A/EP251202a (Fermi GBM team, GCN 42933; Bala et al., GCN 42957; Zhang et al., GCN 42937; Liang et al., GCN 42946) using the IO:O optical camera on the 2m robotic Liverpool Telescope. We obtained two epochs, separated by ~30 minutes, of 6x120s exposures with the SDSS r filter starting at 2025-12-03 03:24: UT, approximately 25.8 hours after trigger.

We report detections in both epochs, at the position of the afterglow first reported by Li et al., GCN 42934:

MJD (mid) T_mid-T_0 Filter Mag. (AB) 61012.15590 25.89 h r 19.99 ± 0.05 61012.17610 26.38 h r 20.18 ± 0.09

The seeing was poor throughout the observations, with the second epoch being more affected. The photometry was calibrated using nearby PanSTARRS secondary standards and was not corrected for extinction.

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