TITLE: GCN CIRCULAR NUMBER: 45042 SUBJECT: EP260623a: FTW optical and NIR observations DATE: 26/06/25 08:19:33 GMT FROM: Malte Busmann at Ludwig-Maximilians-Universität München <m.busmann@physik.lmu.de> Malte Busmann (LMU), Julius Gassert (LMU/CMU), Xander Hall (CMU), Brendan O'Connor (CMU), Daniel Gruen (LMU), and Antonella Palmese (CMU) report: We observed the counterpart of EP260623a (Wang et al., GCNs 45020 and 45035; Li et al., GCN 45021; Izzo et al., GCN 45022; Angulo et al., GCN 45024; Brivio et al., GCN 45025; Jiang et al., GCN 45026; Li et al., GCN 45027; Jelinek et al., GCN 45029; Lee et al., GCN 45030; Saikia et al., GCN 45034; Bochenek & Perley, GCN 45040) with the Three Channel Imager (3KK) at the Fraunhofer Telescope at Wendelstein Observatory (FTW) in the r, i and J band simultaneously for 20 x 180 s starting at 2026-06-24T23:13:34 UT (1.85 days after the trigger). We detect the counterpart in all bands and measure an r-band magnitude of r = 23.93 ± 0.22 AB mag. The magnitude is calibrated against the PS1 catalog and not corrected for Galactic extinction. We thank Christoph Ries from the Wendelstein Observatory for obtaining these observations. View this GCN Circular online at https://gcn.nasa.gov/circulars/45042. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...