TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4612 SUBJECT: GRB050121b: optical observation DATE: 06/01/28 02:17:21 GMT FROM: Alexei Pozanenko at IKI, Moscow D. Sharapov (MAO, and NOT La Palma), M. Ibrahimov (MAO), A. Pozanenko (IKI), V. Rumyantsev (CrAO) on behalf of larger GRB follow up collaboration report: We observed error box of GRB051221b (Boyd et al., GCN 4376) with 1.5m telescope of Maidanak Astronomical Observatory on Dec. 22 between (UT) 15:41 and 16:06. A set of 7x180 s images were obtained in R-band. We do not detect the object at the location of the candidate optical counterpart reported by Halpern & Tyagi (GCN 4381). Limiting magnitude of the stacked image is based on USNO-B1.0: Obs. time, Exposure, mag.(UL),Seeing (UT) (s) Dec.22 15:41 - 16:06 1260 22.3 1.2" Combined images can be found at http://grb.rssi.ru/GRB051221b/grb051221b_051222_R_AZT22.jpg The message may be cited.