TITLE: GCN CIRCULAR NUMBER: 12719 SUBJECT: GRB111222A: GMG optical observation DATE: 11/12/25 02:09:23 GMT FROM: Dong Xu at Weizmann Inst D. Xu (WIS/NAOC), X.-H. Zhao, J.-M. Bai (YNAO), J.-R. Mao (KASI/YNAO) report: We observed the field of GRB 111222A (Hurley et al., GCN 12714; Grupe et al., GCN 12716; Siegel et al., GCN 12717) with the 2.4m GMG telescope equipped with YFOSC. Observations started at 17:34 UT on 2011-12-24 (i.e., 50.717 hrs after the burst) in a seeing of ~3.2", and 3x600s SDSS r-band and 3x600s SDSS z-band images were obtained. As noted in GCN 12717, there was a SDSS star present at the UVOT position which has the following mags: u=22.34+/-0.30 g=19.47+/-0.01 r=18.08+/-0.01 i=16.66+/-0.01 z=15.85+/-0.01. The star had r=18.08+/-0.01 mag and z=15.83+/-0.02 mag in our stacked images (calibrated with nearby SDSS stars), being consistent with the SDSS r- and z-band archival mags. We thank the GMG staff, especially J.-J. Zhang for performing these observations.