{
  "bibcode": "2025GCN.42639....1W",
  "submittedHow": "web",
  "submitter": "SVOM_group <svomgroup@bao.ac.cn>",
  "subject": "GRB 251111A: LCO optical observation",
  "circularId": 42639,
  "format": "text/markdown",
  "createdOn": 1762847943935,
  "body": "C. Wu (NAOC), L. P. Xin, Xuhui Han, J. T. Palmerio (CEA/Irfu), D. Turpin, A. Saccardi, B. Cordier  report on behalf of the SVOM mission team:\n\nWe observed the field of GRB 251111A (SVOM/ECLAIRs, Cheng et al. GCN 42637) with the LCO 1m telescope at Cerro Tololo Inter-American Observatory equipped with the Sinistro instrument. Our observation started at 2025-11-11T05:31:30.632 about 21.21 minutes after the SVOM/ECLAIRs T0 time.\n\nWe obtained a sequence of 3x200 s exposures in the SDSS r band. The optical counterpart reported by SVOM/COLIBRÍ (FM-GFT) (López-Cámara et al., GCN 42638) is clearly detected in our stacked image. We measure an AB magnitude of  r = 21.52 ± 0.15  at a midtime of Tmid − T0 = 26.63 min after the trigger.\n\nThe photometry was calibrated against nearby Pan-STARRS1 stars and no correction for Galactic dust extinction was applied.\n\n\nThis project is funded by the SVOM collaboration.\n\n",
  "eventId": "GRB 251111A"
}