TITLE: GCN CIRCULAR NUMBER: 44905 SUBJECT: GRB 260610B: DDOTI optical observations DATE: 26/06/11 06:31:15 GMT FROM: Alan Watson at UNAM <alan@astro.unam.mx> Alan M. Watson (UNAM), Camila Angulo Valdez (UNAM), Rosa L. Becerra (UNAM), Nat Butler (ASU), Tsvetelina Dimitrova (ASU), William H. Lee (UNAM), and Margarita Pereyra (UNAM) report: We observed the field of GRB 260610B (Fermi Team, GCN Circ. 44901) with the DDOTI wide-field imager at the Observatorio Astronómico Nacional on Sierra San Pedro Mártir from 2026-06-11 04:53 to 05:44 UTC (5.1 to 5.9 hours after the trigger) obtaining total exposure of 27 minutes. We detect the candidate afterglow GOTO26fua/AT2026owq reported by O'Neill et al. (GCN Circ. 44903) with a preliminary AB magnitude of: w = 18.82 +/- 0.04 Compared to the observations reported by O'Neill et al. at 0.21 hours, the candidate continues to fade and has an estimated temporal decay index of approximately −0.6, in agreement with that measured by O'Neill et al. between 0.21 and 1.4 hours. We thank the staff of the Observatorio Astronómico Nacional on the Sierra of San Pedro Mártir. View this GCN Circular online at https://gcn.nasa.gov/circulars/44905. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...