TITLE: GCN CIRCULAR NUMBER: 15711 SUBJECT: GRB 131231A: AAO optical observations DATE: 14/01/09 16:06:01 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Volnova (IKI), R. Inasaridze (AAO), G. Inasaridze (AAO), V. Zhuzhunadze (AAO), Yu. Krugly (IA KhNU), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the optical counterpart of the Fermi/LAT GRB 131231A (Sonbas et al., GCN 15640; Xu et al. GCN 15641) with AS-32 (0.7m) telescope of Abastumani Observatory on Jan. 3, 4, and 5. We obtained several unfiltered images of 120 s exposure during each observational set. On stacked images we clearly detect the afterglow. The photometry based on the reference stars, R-mag, from Halpern (GCN 15646) is following: Date T_start t-t0, exp, OT (UT) mid, d s 2014-01-03 17:08:16 3.54893 33x120 20.26 ± 0.06 2014-01-04 16:53:04 4.53207 29x120 20.32 ± 0.08 2014-01-05 15:59:46 5.50061 34x120 20.74 ± 0.13