TITLE: GCN CIRCULAR NUMBER: 44906 SUBJECT: EP260610b: COLIBRÍ optical observations DATE: 26/06/11 06:56:12 GMT FROM: enriquemm@astro.unam.mx Enrique Moreno Méndez (UNAM), Dalya Akl (NYUAD), Rosa L. Becerra (UNAM), Stéphane Basa (UAR Pytheas), William H. Lee (UNAM), Edilberto Aguilar-Ruiz (UNAM), Jean-Luc Atteia (IRAP), Camila Angulo (UNAM), Sarah Antier (IJCLAB), Nathaniel R. Butler (ASU), Damien Dornic (CPPM), Jean-Grégoire Ducoin (CPPM), Francis Fortin (IRAP), Leonardo García García (UNAM), Ramandeep Gill (UNAM), Noémie Globus (UNAM), Marion Guelfand (CPPM), Asuka Kuwata (UNAM), Massimiliano Lincetto (CPPM), Nikos Mandarakas (LAM), Diego López-Cámara (UNAM), Francesco Magnani (CPPM), Margarita Pereyra (UNAM), Ny Avo Rakotondrainibe (LAM), Fredd Sánchez Álvarez (UNAM), Benjamin Schneider (LAM) and Antonio de Ugarte Postigo (LAM) report: We imaged the field of the EP260610b (Wu et al., GCN Circ. 44895) using the DDRAGO two-channel wide-field imager on the COLIBRÍ telescope. We observed from 2026-06-11 05:16 to 06:32 UTC (from 16.48 to 17.73 hours after the trigger) and obtained 54 minutes of simultaneous exposure in the r/z filters. The data were reduced and coadded with the ASU COLIBRÍ pipeline. The photometry was calibrated using nearby stars from the PanSTARRS DR1 catalog, is in the AB system, and is not corrected for Galactic extinction. We marginally detect the optical counterpart reported by Levan et al., GCN Circ. 44897, in the r band, at a preliminary magnitude of: r ≈ 23.7, In z, we do not detect the source down to the following 3-sigma limit: z > 22.0. These values are consistent with those reported by Gemini (Levan et al., GCN Circ. 44897), SVOM/VT (Xin et al., GCN Circ. 44900), NOT (Zhu et al., GCN Circ. 44902) and MAO/AZT-22 (Burkhonov et al., GCN Circ. 44904). We thank the staff of the Observatorio Astronómico Nacional at Sierra de San Pedro Mártir, as well as the technical and engineering teams at CEA, CPPM, IRAP, LAM, OHP, OSU Pytheas, and UNAM. COLIBRÍ is an astronomical observatory developed and operated jointly by France (AMU, CNES and CNRS) and Mexico (UNAM and SECIHTI). It is located at the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir, Baja California, Mexico. View this GCN Circular online at https://gcn.nasa.gov/circulars/44906. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...