{
  "format": "text/plain",
  "eventId": "GRB 260610B",
  "circularId": 44946,
  "subject": "GRB 260610B: Terskol optical observations",
  "body": "N. Pankov (IKI), A. Salakhotdinova (INASAN), A. Shein (INASAN), E. Postnikova (INASAN), A. Pozanenko (IKI), A. Moskvitin (SAO RAS), A. Volnova (IKI) report on behalf of IKI-GRB-FuN:\n\nWe observed the field of GRB 260610B (The Fermi GBM team, GCN 44891; GCN 44901) with the Zeiss-2000 2-meter telescope of the Terskol Observatory on epochs 2026-06-11 and 2026-06-12. The R-band observations were carried out using the CCD-photometer. In the first epoch we acquired a series of 3x120+12x120 sec images, while in the latter epoch 9x120 sec images were obtained. The OT (O'Neill et al., GCN 44903; Watson et al., GCN 44905; Zhu et al., GCN 44909; Gillanders et al., GCN 44910; Akl et al., GCN 44911; O'Neill et al., GCN 44914; Moskvitin et al., GCN 44918; Jackson-Horne et al., GCN 44919; Izzo, GCN 44920; Li et al., GCN 44921; Bochenek and Perley, GCN 44927; Moskvitin et al., GCN 44929; Akl et al., GCN 44930; Bochenek & Perley, GCN 44932) is clearly detected in our co-add images. The observational properties and preliminary photometry are provided further:\n\nDate       UTstart    t-T0    Exp.       Filter   Mag  Err    UL  \n                     (mid,d) (n*s)                           (3-sigma)\n2026-06-11 21:33:51 1.48481  3x120+12x90   R     19.81 0.06   22.4\n2026-06-12 19:46:19 2.40802  9x120         R     20.70 0.13   22.3\n\nThe photometry is based on nearby SDSS stars (R-magnitudes obtained via Lupton 2005 transformation equations; Moskvitin et al., GCN 44918) and not corrected for the Galactic extinction.",
  "createdOn": 1781513187827,
  "submittedHow": "web",
  "submitter": "Nicolai Pankov at IKI <colinsergesen@gmail.com>"
}