{
  "circularId": 45501,
  "eventId": "GRB 260903A",
  "submittedHow": "web",
  "submitter": "SVOM_group <svomgroup@bao.ac.cn>",
  "eventType": [
    "GRB",
    "Optical Transient"
  ],
  "body": "Y.X. Guan(GXU), A. Saccardi (CEA/Irfu), S.J.Yin (GXU),  C. Wu, L.P. Xin (NAOC), Yunyu Shi (GXU), D. Turpin (CEA/Irfu), R.-C. Chen (NJU), T. Xiao (GXU) report on behalf of the SVOM mission team:\n \n \nWe observed the field of the SVOM/ECLAIRs GRB 260903A (Brunet et al., GCN 45499) with the LCO 1m telescope at Siding Spring Observatory equipped with the Sinistro instrument.\n \nOur observation started on 2026-09-03T13:06:41.486 UT (about 29.36 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\nAn uncatalogued optical source compared to DESI DR10  catalogue is clearly detected in our images within the  ECLAIRs  localization error circle (Brunet et al., GCN 45499).  Its position is  R.A., Dec. 25.77241, 11.43678  degrees:\nR.A. (J2000) = 01h43m05.37     \nDec. (J2000) = +11d26m12.4\nwith an uncertainty of ~0.5 arcsec.\n\n\nWe measure the following magnitudes calibrated against the DESI DR10 catalog, and not corrected for Galactic extinction:\n \nr = 17.91 +/- 0.02 AB (mid-time  38.66 min after the trigger);\nz = 17.69 +/- 0.13 AB (mid-time 31.01 min after the trigger).\n \nThis project is funded by the SVOM collaboration.",
  "subject": "GRB 260903A: LCO optical counterpart detection",
  "createdOn": 1788448283177,
  "format": "text/plain"
}