{
  "submittedHow": "web",
  "eventType": [
    "GRB",
    "Optical Transient"
  ],
  "submitter": "Nicolai Pankov at IKI <colinsergesen@gmail.com>",
  "circularId": 45774,
  "createdOn": 1790585955255,
  "body": "N. Pankov (IKI), A. Pozanenko (IKI), R. Ya. Inasaridze (AbAO), M. Zhuzhunadze (AbAO), A. Volnova (IKI), A. Moskvitin (SAO RAS) report on behalf of IKI-GRB-FuN:\n \nWe observed the field of a bright GRB 260924A (The Fermi GBM team, GCN 45712; D'Elia, GCN 45713; Salunke et al., GCN 45720; Holzmann Airasca et al., GCN  45721; Waratkar et al., GCN 45732; Yu et al., GCN 45741; Gupta et al., GCN 45750; Ridnaia et al., GCN  45751) at z=3.51 (Castro-Tirado et al., GCN 45740) with the AS-32 0.7m telescope of the Abastumani Astrophysical Observatory (AbAO) on 2 subsequent nights 2026-09-26 and 2026-09-27. The first observation has started at 00:31:30 UT, i.e, ~2 days since trigger. Both observations were taken in the R-band using a CCD-photometer. The optical afterglow (Hu et al., GCN 45717, Izzo et al., GCN 45718; Vijaykumar et al., GCN 45734; Klingler et al., GCN 45735; Ma et al., GCN 45736; Novotny et al., GCN 45743; Aryan et al., GCN 45748; Li et al., GCN 45728; Fortin et al., GCN 45759; Mo et al., GCN 45762) is detected in the co-add image of the first night, while absent in the second night co-add. Preliminary photometry and observation details are listed below:\n \nDate       UTstart  Exptime t-T0     Filter OT   Err. UL(3sigma)\n                    (nxs)   (days)                  \n2026-09-26 00:31:30 68*60   1.99453  R      20.0 0.3  20.3\n2026-09-27 00:16:21 90*60   2.99164  R      n/d  n/d  20.0\n \nThe photometry was calibrated using nearby stars from USNO-B1.0 (R2 magnitudes) and \nhas not been corrected for the Galactic extinction.",
  "eventId": "GRB 260924A",
  "format": "text/plain",
  "subject": "GRB 260924A: AbAO optical observations"
}