TITLE: GCN CIRCULAR NUMBER: 44518 SUBJECT: GRB 260510B: LCO optical upper limits DATE: 26/05/10 15:18:38 GMT FROM: SVOM_group <svomgroup@bao.ac.cn> A. Saccardi (CEA/Irfu), C. Wu (NAOC), L. Zhang (IHEP), Y. H. Cheng (YNU), report on behalf of the SVOM mission team: We observed the field of GRB 260510B detected by SVOM (Saccardi et al., GCN 44515) with the LCO 1m telescope at Siding Spring Observatory equipped with the Sinistro instrument. Our observation started on 2026-05-10 at 12:33:06 UT (about 14 min after the trigger) and we obtained 2x200 s exposures in the SDSS r and 3x200 s exposures in the Pan-STARRS z filters. In the stacked images, we do not detect any new source within the SVOM/ECLAIRs error box. We measure the following upper limits calibrated against the DESI DR10 catalog, and not corrected for Galactic extinction: r > 20.7 AB (5-sigma, mid-time 1.9 hr after the trigger); z > 20.0 AB (5-sigma, mid-time 19 min after the trigger). This project is funded by the SVOM collaboration. View this GCN Circular online at https://gcn.nasa.gov/circulars/44518. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...