GCN Circular 38878
Subject
EP250108a: Liverpool Telescope likely optical counterpart
Date
2025-01-09T21:42:48Z (2 days ago)
From
Rob Eyles-Ferris at U of Leicester <raje1@leicester.ac.uk>
Via
Web form
R. Eyles-Ferris (U of Leicester) reports:
We observed the field of the X-ray transient EP250108a (Li et al., GCN 38861) using the IO:O on the 2m Liverpool Telescope. We obtained 6x200s exposures in the SDSS g’ filter starting at 2025-01-09 19:59:08 UT, approximately 31.5 hours after the trigger.
We performed image subtraction on the stacked image using a reference Pan-STARRS image and identify a source of g’ = 20.79+/-0.05 with photometry calibrated to Pan-STARRS and not corrected for Galactic extinction. The source is located at RA, Dec = 55.61823, -22.50587 deg, which is equivalent to:
RA (J2000) : 03:42:28.38
Dec (J2000): -22:30:21.1
This source is within the error region of the Einstein Probe detection and is the only source within it in the subtracted image. It is also visible in the individual frames. There is a catalogued DES DR1/2 source with a measured g’ band magnitude of 23.3 and a photometric redshift of 0.882+/-0.379 consistent with our measured position. We suggest this is the host galaxy. Further observations are planned.