TITLE: GCN CIRCULAR NUMBER: 42849 SUBJECT: GRB 251126A: Asiago i-band detection DATE: 25/11/26 21:14:37 GMT FROM: Daniele Bjørn Malesani at Cosmic Dawn Center, Niels Bohr Institute <daniele.malesani@nbi.ku.dk> A. Reguitti (INAF/OAPD), L. Tomasella (INAF/OAPD), D. B. Malesani (DAWN/NIB and Radboud), report on behalf of a larger collaboration: We observed the optical afterglow (Swain et al., GCN 42844; Fu et al., GCN 42848) of GRB 251126A (Caputo et al., GCN 42843) using the 67/92 Schmidt Telescope located at the Asiago observatory (Italy). Observations were carried out using the Sloan i filter. In a single exposure with start time 2025 Nov 26.8252 UT (37.8 min after the Swift/BAT trigger), the afterglow is detected with a magnitude i = 18.27 +- 0.15 (AB), calibrated against nearby stars fron the Pan-STARRS catalog, and not corrected for Galactic extinction. Compared to the earlier optical measurements (Swain et al., GCN 42844; Fu et al., GCN 42848), our images seem to indicate a red r-i color for the optical afterglow. View this GCN Circular online at https://gcn.nasa.gov/circulars/42849. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...