TITLE: GCN CIRCULAR NUMBER: 23406 SUBJECT: GRB 181103A: Nanshan-1m optical upper limit DATE: 18/11/04 11:51:29 GMT FROM: Dong Xu at NAOC/CAS J.H. Liu (XAO), Z.P. Zhu, D. Xu (NAOC), X. Zhang, F.F. Song, Z.X. Li, J.Y. Bai, H.B. Niu, J.Z. Liu, A. Esamdin, L. Ma, Y. Zhang (XAO) report: We observed the field of GRB 181103A (Tohuvavohu et al., GCN 23402) using the Nanshan-1m telescope located at Nanshan, Xinjiang, China. We optained 5กม300s, 1กม400s, 1กม600s R-band frames, starting at 23:07:05 UT on 2018-11-03, i.e, 18.73 hr after the Swift trigger. No optical source was detected in the stacked image at the XRT position (Evans et al, GCN 23403), down to a limiting magnitude of R ~ 21.3 mag at the median time of 19.31hr post-burst, calibrated with the nearby SDSS field.