TITLE: GCN CIRCULAR NUMBER: 12589 SUBJECT: GRB 111123A: GMG optical observation DATE: 11/11/24 02:23:25 GMT FROM: Dong Xu at Weizmann Inst D. Xu (WIS), X.-H. Zhao, J.-R. Mao, J.-M. Bai (YNAO) report: We observed the field of GRB 111123A (Stamatikos et al., GCN 12587) with the 2.4m Gao-Mei-Gu (GMG) telescope equipped with YFOSC, and obtained 3x600s R-band and 3x600s I-band images, starting at 21:00:56 UT on Nov. 23rd (i.e., 2.793 hrs after the burst). Within the XRT SPER error circle (http://www.swift.ac.uk/sper/), no optical source was detected in the stacked I-band image, and a weak and compact source was found in the stacked R-band image at coordinates RA(J2000) = 10:19:23.10 Dec(J2000) = -20:38:41.72 with an uncertainty of ~1" in each coordinate. We caution that the above source may be ascribed to background fluctuation. In this sense, we derive R>~23.7 mag, calibrated with the #0693-0243590 star (R1=17.95 and R2=17.60) in the USNO B1 catalog. Deeper and NIR observations are encouraged. We are grateful to Chuan-Jun Wang, De-Qing Wang, and Yan-Dong Lang for performing these observations. [GCN OPS NOTE(24nov11): Per author's request, Mao was added to the author list.]