TITLE:   GCN CIRCULAR
NUMBER:  37869
SUBJECT: EP241021a: Liverpool Telescope optical follow-up observations
DATE:    24/10/25 09:33:09 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 EP241021a (Hu et al., GCN 37834) using the IO:O optical camera on the 2m robotic Liverpool Telescope. We obtained 6x150s exposures in the SDSS r’ filter starting at 2024-10-24 23:07:43 UT, approximately 3.25 days after the trigger.
 
We report a faint detection in the stacked images of r = 22.43 ± 0.14 mag, at a position consistent with the optical counterpart reported by Fu et al. (GCN 37840) and other optical observations (Fu et al., GCN 37842; Li et al., GCN 37844; Ror et al., GCN 37845; Li et al., GCN 37846; Zheng et al., GCN 37849; Moskvitin and Spiridonova, GCN 37850;  Pugliese et al. GCN 37852; Pérez-Fournon et al. GCN 37858). The photometry was obtained using nearby PanSTARRS standards and was not corrected for extinction. The source faded approximately 0.5 mag in the last 24 hours.