TITLE:   GCN CIRCULAR
NUMBER:  43124
SUBJECT: GRB 251214B: AbAO optical observations
DATE:    25/12/15 14:54:17 GMT
FROM:    Alina Volnova at IKI RAS <alinusss@gmail.com>

A. A. Volnova (IKI), R. Ya. Inasaridze (AbAO), A. S. Pozanenko (IKI), N. S. Pankov (HSE, IKI) report on behalf of IKI-GRB-FuN:

We observed the field of the long GRB 251214B detected by Fermi (Fermi team, GCN 43088), Swift (Eyles-Ferris et al., GCN 43089; Evans et al., GCN 43098; Kuin and Eyles-Ferris, GCN 43105; Burrows et al., GCN 43112), and  GECAM-B (Luo et al., GCN 43113) with the AS-32 0.7m telescope of Abastumani Observatory (AbAO) taking several frames in R-band. The observations started on Dec. 14 at 15:00 UT, i.e., ~ 6 hours after the Swift/BAT trigger. In the stacked image we detect the optical afterglow reported previously (Eyles-Ferris et al., GCN 43089; Kang et al., GCN 43093; Gress et al., GCN 43095; Fu et al., GCN 43097; Gupta et al., GCN 43100; Watson et al., GCN 43103; Kuin and Eyles-Ferris, GCN 43105; Pérez-Fournon et al., GCN 43123). 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)
2025-12-14  15:00:25  0.27325    51*60   R        20.6   0.2   20.7       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.