{
  "body": "A. Volnova (IKI), D. Andreev (INASAN), A. Pozanenko (IKI), A. Moskvitin (SAO), N. Pankov (IKI) report on behalf of IKI-GRB-FuN:\n\nWe observed the field of Einstein Probe fast X-ray transient EP261015a (Li et al., GCN 45956) with the Zeiss-2000 2-meter telescope of the Terskol Observatory on Oct. 17, 2026, starting at 21:30 UT and taking several exposures in R-band.\nThe optical counterpart reported previously (Corcoran et al., GCNs 45955, 45972; Fortin et al., GCN 45991) is not detected in the stacked frame.\nPreliminary photometry and observational details are the following:\n\nDate        UT start  t-T0      Exp,    Filter Obj    Err   UL      Site/Telescope\n                     (mid,days) (n*s)                      (3sigma)\n2026-10-17  21:30:24  2.32810   20*180  R      n/d    n/d   22.8    Terskol/Z2000\n\nThe photometry is based on several nearby stars from the USNO-B1 catalogue (R2 magnitudes) and is not corrected for the Galactic extinction.",
  "circularId": 45997,
  "createdOn": 1792508854560,
  "submittedHow": "web",
  "format": "text/plain",
  "subject": "EP261015a: Terskol Zeiss-2000 optical upper limit",
  "submitter": "Alina Volnova at IKI RAS <alinusss@gmail.com>",
  "eventType": [
    "X-ray Transient"
  ],
  "eventId": "EP261015a"
}