GCN Circular 43230
Subject
GRB 251222A: AbAO optical observations
Event
Date
2025-12-24T11:20:29Z (20 hours ago)
From
Alina Volnova at IKI RAS <alinusss@gmail.com>
Via
Web form
A. A. Volnova (IKI), R. Ya. Inasaridze (AbAO), N. S. Pankov (HSE, IKI), A. S. Pozanenko (IKI) report on behalf of IKI-GRB-FuN:
We observed the field of GRB 251222A (The Fermi GBM team, GCN 43186; Yang et. al, GCN 43188; Preis & Greiner, GCN 43190; Evans, GCN 43191; Beardmore et. al, GCN 43213; Frederiks et. al, GCN 43214; Guo et. al, GCN 43218; Neights et. al, GCN 43222) at z = 3.171 (Saccardi et. al, GCN 43204) with the AS-32 0.7m telescope of Abastumani Observatory (AbAO) taking several 60-second frames in R-band. The observations started on Dec. 23 at UT 18:16:00, i.e., ~ 1 day after the trigger. In the stacked image we detect the optical counterpart reported previously (Palmerio et. al, GCN 43189; An et. al, GCN 43194; Calapai et. al, GCN 43195; Durbak et. al, GCN 43197; Li et. al, GCN 43203; Saccardi et. al, GCN 43208; Gupta et. al, GCN 43207; Saccardi et. al, GCN 43204; Kumar et. al, GCN 43209; Pérez-Fournon et. al, GCN 43212; Gupta et al., GCN 43224; Globus et al., GCN 43225; Pankov et al., GCN 43226; Freeberg et al., GCN 43229). Preliminary photometry and observational details are the following:
Date UT start t-T0 Exp. Filter Obj. Err. UL Site/Telescope
(mid,days) (n*s) (3sigma)
2025-12-23 18:16:00 1.07935 72*60 R 20.46 0.18 21.3 AbAO/AS-32
The photometry is based on several nearby stars from the USNO-B1 catalogue (R2 magnitudes) and is not corrected for the Galactic extinction.