TITLE:   GCN CIRCULAR
NUMBER:  41991
SUBJECT: GRB250925A: Liverpool Telescope optical observations
DATE:    25/09/25 21:46:51 GMT
FROM:    A. Bochenek at Liverpool John Moores University <a.m.bochenek@2023.ljmu.ac.uk>

A. Bochenek and D. A. Perley (LJMU) report:
 
We observed the field of GRB250925a detected by Swift (Dichiara et al., GCN 41915) using the IO:O optical camera on the 2m robotic Liverpool Telescope. We obtained 5x100s exposures in the SDSS i’ filter starting at 2025-09-25 20:59:51 UT, approximately 3.92 hours after the trigger.
 
We report a detection in the stacked image at the position of the candidate optical counterpart (Corcoran et al., GCN 41990), inside the XRT error field (Page et al., GCN 41988). The magnitude of the candidate afterglow is i = 20.78 ± 0.03. The photometry was calibrated using nearby PanSTARRS secondary standards and was not corrected for extinction.