TITLE: GCN CIRCULAR NUMBER: 43115 SUBJECT: GRB 251203B: AbAO optical observations DATE: 25/12/15 11:12:25 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 SWOM trigger sb25120304 (Brunet et al. GCN 42973) with the AS-32 0.7m telescope of Abastumani Observatory (AbAO) taking several frames in R-band. The observations started on Dec. 3 at 21:00 UT, i.e., ~ 3 hours after the SWOM trigger. In the stacked image, we do not detect any new source within the MXT error circle. The star Gaia DR3 2534635509050352256 reported previously (Palmerio et al., GCB 42978; Malesani et al., GCN 42979; Perez-Garcia et al., GCN 42982) is consistent with two USNO-B1.0 sources 0900-0013627 (RA(J2000) = 01:13:26.6548920, Dec(J2000) = +00:01:08.382180; R1 = 13.31) and 0900-0013628 (RA(J2000) = 01:13:26.8108752, Dec(J2000) = +00:01:08.040144; R2 = 13.83) and is clearly detected in the stacked frame. Its R-magnitude is brighter ~0.2 mag than the catalogue USNO-B1.0 R1 value, that supports the nature of the trigger as a star flare. Photometry and observational details are the following: Date UT start t-T0 Exp. Filter Obj. Err. UL Site/Telescope (mid,days) (n*s) (3sigma) 2025-12-03 21:00:00 0.15311 60*20 R 13.13 0.02 19.5 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. View this GCN Circular online at https://gcn.nasa.gov/circulars/43115. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...