{
  "body": "C. Wu (NAOC), A. Saccardi (CEA/Irfu), L. P. Xin (NAOC), J. T. Palmerio (CEA/Irfu), B. \nCordier (CEA/Irfu), Y. N. Ma (NAOC), D. Zhao (NAOC) report on behalf of the SVOM mission team:\n\nWe observed the field of the GRB 250910A detected by SVOM/ECLAIRs (Ma et al., GCN 41769) with the LCO 1m telescope at Cerro Tololo Interamerican Observatory equipped with the Sinistro instrument.\n\nOur observation started on 2025-09-10 at 05:03:46 UT (~1.79  hr after the trigger) and we obtained 3x200 s exposures using the SDSS r filter.\n\nIn the stacked image, we did not detect any new optical source at the SVOM/MXT position (Götz et al., GCN 41770). We derived the following upper limit r > 20.8 mag (5-sigma) calibrated using nearby stars from the UCAC4 catalog and not corrected for Galactic extinction.\n\nThis project is funded by the SVOM collaboration.\n",
  "bibcode": "2025GCN.41772....1W",
  "subject": "GRB 250910A: LCO optical upper limit",
  "circularId": 41772,
  "createdOn": 1757490190348,
  "submittedHow": "web",
  "format": "text/plain",
  "submitter": "SVOM_group <svomgroup@bao.ac.cn>",
  "eventId": "GRB 250910A"
}