TITLE: GCN CIRCULAR NUMBER: 43676 SUBJECT: GRB260208A: Liverpool Telescope optical follow-up observations DATE: 26/02/10 00:51:14 GMT FROM: A. Bochenek at Liverpool John Moores University <a.m.bochenek@2023.ljmu.ac.uk> A. Bochenek, J. Wise, D. A. Perley (LJMU), report: We observed the field of GRB260208a (Fermi GBM team, GCN 43635; Sonawane et al., GCN 43642; Longo et al., GCN 43645; Luo et al., GCN 43658; Mukherjee et al. GCN 43673; Waratkar et al., GCN 43674, Cheung et al., GCN 43675) using the IO:O optical camera on the 2m robotic Liverpool Telescope. We obtained two epochs of 3x100s exposures in the SDSS r, i, z filters and 4x100s in SDSS g, starting at 2026-02-09 02:49:11 UT, approximately 21.7 hours after trigger, and the second epoch at 24.4 hours after the trigger. We report detections in stacked images in all filters at the position first reported by Lipunov et al., GCN 43640 and Wortley et al., GCN 43641, although we note some exposures were discarded due to poor seeing or telescope movement. MJD (mid) T_mid-T_0 Filter Mag. (AB) 61080.11951 21.74 h z 20.03 ± 0.16 61080.12395 21.85 h i 20.24 ± 0.25 61080.12842 21.95 h r 20.75 ± 0.10 61080.13428 22.09 h g 21.34 ± 0.24 61080.22567 24.29 h z 20.35 ± 0.11 61080.23080 24.41 h i 20.49 ± 0.09 61060.04432 24.54 h r 20.97 ± 0.15 61080.23595 24.64 h g 21.39 ± 0.14 The photometry is consistent with measurements taken at similar time by Dimple et al., GCN 43661 and Magnani et al., GCN 43664. The photometry was obtained using nearby PanSTARRS secondary standards and was not corrected for extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/43676. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...