{
  "submittedHow": "web",
  "submitter": "SVOM_group <svomgroup@bao.ac.cn>",
  "circularId": 44535,
  "createdOn": 1778484044930,
  "format": "text/plain",
  "subject": "GRB 260511A: LCO optical afterglow detection",
  "bibcode": "2026GCN.44535....1S",
  "body": "A. Saccardi (CEA/Irfu), C. Wu (NAOC), L. Zhang (IHEP), D. Kong (GXU), report on behalf of the SVOM mission team:\n\nWe 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.\n\nOur 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.\n\nThe 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:\n\nr = 18.88 +/- 0.02  AB (mid-time 21 min after the trigger);\nz = 18.05 +/- 0.04 AB (mid-time 15 min after the trigger).\n\nThis project is funded by the SVOM collaboration.",
  "eventId": "GRB 260511A"
}