TITLE: GCN CIRCULAR NUMBER: 44535 SUBJECT: GRB 260511A: LCO optical afterglow detection DATE: 26/05/11 07:20:44 GMT FROM: SVOM_group <svomgroup@bao.ac.cn> A. Saccardi (CEA/Irfu), C. Wu (NAOC), L. Zhang (IHEP), D. Kong (GXU), report on behalf of the SVOM mission team: We observed the field of the SVOM/ECLAIRs and Fermi/GBM GRB 260511A (Godet et al., GCN 44532; Fermi GBM Team, GCN 44529) with the LCO 1m telescope at Cerro Tololo Observatory equipped with the Sinistro instrument. Our observation started on 2026-05-11 at 06:24:46 UT (about 11 min after the trigger) and we obtained 3x200 s exposures in the SDSS r and 3x200 s exposures in the Pan-STARRS z filters. The optical counterpart (Jiang et al., GCN 44533; Akl et al. GCN 44534) is clearly detected in our images. We measure the following magnitudes calibrated against the Pan-STARRS DR1 catalog, and not corrected for Galactic extinction: r = 18.88 +/- 0.02 AB (mid-time 21 min after the trigger); z = 18.05 +/- 0.04 AB (mid-time 15 min after the trigger). This project is funded by the SVOM collaboration. View this GCN Circular online at https://gcn.nasa.gov/circulars/44535. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...