TITLE:   GCN CIRCULAR
NUMBER:  41590
SUBJECT: EP250828a: Liverpool Telescope upper limits
DATE:    25/08/29 09:28:38 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 the fast X-ray transient EP250828a (Liu et al., GCN 41574) 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 2025-08-29 22:33:53 UT, approximately 15 hours after the trigger.
 
We do not detect the reported optical counterpart (Taguchi et al., GCN 41582; Yao et al., GCN 41583) or any new objects within the EP/FXT error region of the transient (Liu et al., GCN 41574). The 3-sigma limiting magnitudes on the stacked images are r > 23.7 mag and i > 23.6 mag. This is consistent with the detection of an optical counterpart candidate by NOT at r ~ 24.4 at 15.2 hours post trigger (Fu et al., GCN 41584).