{
  "bibcode": "2025GCN.42710....1V",
  "submittedHow": "web",
  "circularId": 42710,
  "body": "A. Volnova (IKI), E. Klunko (ISTP), A. Pozanenko (IKI) report on behalf of IKI-GRB-FuN:\n\nWe observed the field of the GRB 251111A (Cheng et al., GCN 42637) with the AZT-33IK 1.5m telescope of the Sayan Solar Observatory (Mondy) in the R-filter starting Nov., 11, 2025, UT 16:26:22, and taking several frames with 120 s exposures. In the stacked frame we do not detect the optical counterpart (López-Cámara et al., GCN 42638; Wu et al., GCNs 42639, 42641; Ma et al., GCN 42647). Preliminary photometry is the following:\n\nDate        UT start  t-T0       Exp.    Filter  OT     Err.  UL     \n                     (mid,days)  (n*s)                       (3sigma)\n2025-11-11  16:26:22  0.48686    25*120  R       n/d    n/d   22.1\n\nThe photometry is based on several nearby SDSS stars (R-magnitudes Lupton's transformation) and is not corrected for the Galactic extinction, all magnitudes are in Vega system.",
  "submitter": "Alina Volnova at IKI RAS <alinusss@gmail.com>",
  "createdOn": 1763366729867,
  "format": "text/plain",
  "eventId": "GRB 251111A",
  "subject": "GRB 251111A: Mondy optical upper limit"
}