TITLE: GCN CIRCULAR NUMBER: 44516 SUBJECT: GRB 260509A: Liverpool Telescope optical observations DATE: 26/05/10 13:20:53 GMT FROM: A. Bochenek at Liverpool John Moores University <a.m.bochenek@2023.ljmu.ac.uk> A. Bochenek, D. A. Perley (LJMU), report: We observed the field of GRB 260509A (Götz et al., GCN 44504) using the IO:O optical camera on the 2m robotic Liverpool Telescope. We obtained 4x100s exposures in SDSS griz filters, starting at 2026-05-09 23:08:01 UT, approximately 1.28 hours after trigger. We detect a source in all filters at the position reported by O'Neill et al. (GCN 44505), observed also by Saccardi et al. (GCN 44506), Wu et al. (GCN 44507), Sánchez Álvarez et al. (GCN 44509), Zheng et al. (GCN 44510), Lipunov et al. (GCN 44512), and Belkin et al. (GCN 44513): MJD (mid) T_mid-T_0 Filter Mag. (AB) 61169.96654 1.34 h g 20.00 ± 0.05 61169.97218 1.48 h r 19.83 ± 0.06 61169.97779 1.61 h i 19.81 ± 0.09 61169.98272 1.73 h z 19.61 ± 0.09 The photometry was calibrated using nearby PanSTARRS secondary standards and was not corrected for extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/44516. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...