TITLE: GCN CIRCULAR NUMBER: 45025 SUBJECT: EP260623a: REM optical/NIR afterglow detection DATE: 26/06/23 10:05:07 GMT FROM: Riccardo Brivio at INAF-OAB <riccardo.brivio@inaf.it> R. Brivio, M. Ferro, P. D'Avanzo, S. Covino, D. Fugazza (INAF-OAB), L. Izzo (INAF-OACN and DARK/NBI), D. B. Malesani (DAWN/NBI and Radboud), A. Melandri (INAF-OAR) report on behalf of the REM team: We observed the field of EP260623a, detected by EP/WXT (Wang et al., GCN 45020) with the REM 60 cm robotic telescope located at the ESO observatory of La Silla (Chile). The observations were carried out in the g, r, i, z, K bands, started on 2026-06-23 at 03:57:45 UT (i.e. 1.1 hr after the burst) and lasted for about 1 hr. From preliminary photometry, we detect the optical/NIR counterpart (Li et al., GCN 45021; Izzo et al., GCN 45022; Angulo et al., GCN 45024) with the following magnitudes: r = 16.35 +/- 0.04 (AB; calibrated against the Pan-STARRS catalogue), at a mid-time of 1.1 hr after the trigger; K = 13.51 +/- 0.17 (Vega; calibrated against the 2MASS catalogue), at a mid-time of 1.1 hr after the trigger. View this GCN Circular online at https://gcn.nasa.gov/circulars/45025. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...