TITLE: GCN CIRCULAR NUMBER: 44659 SUBJECT: GRB 260516D: LCO optical observations DATE: 26/05/17 08:22:30 GMT FROM: SVOM_group <svomgroup@bao.ac.cn> C. Wu (NAOC), A. Saccardi (CEA/Irfu), L.P. Xin (NAOC) report on behalf of the SVOM mission team: We observed the field of the SVOM/ECLAIRs GRB 260516D (Brunet et al., GCN 44649) with the LCO 1m telescope at McDonald Observatory and Cerro Tololo equipped with the Sinistro instrument. Our observation started on 2026-05-17 at 06:26:56 UT (about 9.79 hr 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 (Li et al., GCN 44654; Mohan et al., GCN 44655; García et al., GCN 44657) with redshift of 1.801 (Izzo et al., GCN 44656) is faintly detected in our images. We measure the following magnitudes calibrated against the Pan-STARRS DR1 catalog, and not corrected for Galactic extinction: r = 21.75 +/- 0.10 AB (mid-time 9.88 hr after the trigger); z > 21.2 AB (3-sigma, mid-time 10.00 hr after the trigger). This project is funded by the SVOM collaboration. View this GCN Circular online at https://gcn.nasa.gov/circulars/44659. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...