TITLE: GCN CIRCULAR NUMBER: 45202 SUBJECT: EP260723a: Liverpool Telescope likely optical counterpart DATE: 26/07/24 07:25:20 GMT FROM: Rob Eyles-Ferris at U of Leicester <raje1@leicester.ac.uk> R. A. J. Eyles-Ferris (Leicester), G. Corcoran (UCD), D. B. Malesani (DAWN/NBI and Radboud) and R. L. C. Starling (Leicester) report on behalf of a larger collaboration: We observed the field of the Einstein Probe fast X-ray transient EP260723a (Zhang et al., GCN 45201) with the 2m Liverpool Telescope on La Palma using the IO:O instrument. We obtained 4x150 s and 5 x150 s exposures in each of the SDSS r’ and g’ filters respectively starting at 2026-07-24 04:35:57 UT, approximately 10.8 hours after the X-ray detection. We performed image subtraction on the stacked images using reference images from Pan-STARRS and also compared the stacked and reference images manually. In our r-band subtraction and in the stacked image, we identify a new source within the EP/WXT localisation at a position of: RA 2.97513 (00:11:54.03) Dec -12.09839 (-12:05:54.2) We measure an AB magnitude of r = 21.86 +/- 0.11 and a g-band 5-sigma upper limit at the position of g > 22.25. Our photometry is calibrated to PanSTARRS and not corrected for Galactic extinction. We note the presence of a source in the Legacy Survey consistent with our candidate’s position at a magnitude of r = 23.62 +/- 0.15 and a photometric redshift of 0.91 +/- 0.13. We suggest this could be the host galaxy of EP260723a. View this GCN Circular online at https://gcn.nasa.gov/circulars/45202. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...