TITLE: GCN CIRCULAR NUMBER: 43661 SUBJECT: GRB 260208A: Liverpool Telescope optical detection DATE: 26/02/09 10:00:09 GMT FROM: Dimple at University of Birmingham <dimplepanchal96@gmail.com> Dimple (U. Birmingham), B. P. Gompertz (U. Birmingham), D. O'Neill (U. Birmingham), and D. B. Malesani (DAWN/NBI and Radboud) report on behalf of a larger collaboration: We conducted follow-up observations of GRB 260208A (Fermi GBM team, GCN 43635; Sonawane et al., GCN 43642; Longo et al., GCN 43645; Luo et al., GCN 43658) with the IO:O camera on the 2m robotic Liverpool Telescope (LT). Observations began at 03:49:38 UT on 2026-02-09, ~22.8 hr after the Fermi trigger, and consisted of 5 x 180 s exposures in each of the SDSS r and i filters. We detect the optical counterpart (Podesta et al., GCN 43640; Wortley et al., GCN 43641; Ma et al., GCN 43655; Ahumada et al., GCN 43657; also detected in X-rays, Dichiara et al., GCN 43652) in both filters, and measure an AB magnitude of r = 20.63 ± 0.04. Magnitudes are calibrated against nearby Pan-STARRS stars and are not corrected for Galactic extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/43661. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...