TITLE: GCN CIRCULAR NUMBER: 40677 SUBJECT: GRB 250610B: LT detection of the optical counterpart DATE: 25/06/10 23:30:06 GMT FROM: Ben Gompertz at U of Birmingham B. P. Gompertz (U. Birmingham), Dimple (U. Birmingham), A. Martin-Carrillo (UCD) and G. Corcoran (UCD) report on behalf of a larger collaboration: We initiated follow-up observations of GRB 250610B (Saccardi et al., GCN 40671) with the IO:O camera on the 2m robotic Liverpool Telescope (LT). Observations began at 22:24:56 UT, ~5.85 hr after the SVOM/ECLAIRs trigger, and consisted of 7x120 s and 10x120 s exposures in the SDSS g and i filters, respectively. We detect the optical counterpart (Schneider et al., GCN 40676) with AB magnitudes of g = 21.38 ± 0.11 and i = 21.02 ± 0.06. Magnitudes are calibrated against nearby Pan-STARRS stars and are not corrected for Galactic extinction.