TITLE: GCN CIRCULAR NUMBER: 20417 SUBJECT: LIGO/Virgo G268556: NOWT of EWE, Xinglong 0.6/0.9m, Xuyi 1m optical upper limits of ATLAS17aeu and a reminder of GCN 20394 DATE: 17/01/10 15:22:53 GMT FROM: Jinzhong Liu at Xinjiang Astronomical Observatory D. Xu (NAOC/CAS), J.Z. Liu, H.B. Niu, Y. Zhang, X. Zhang, G.X. Pu, S.G. Ma, T.Z. Yang, F.F. Song (XAO), X. Zhou, T.M. Zhang (NAOC/CAS), H.B. Zhao, B. Li, G.T. Zhaori (PMO), J.M. Bai, J.R. Mao (YNAO) report on behalf of a Chinese Gravitational Wave collaboration: We have performed tiled observations of LIGO/Virgo G268556 (LVC, GCN 20364) using the Nanshan One-meter Wide field Telescope (NOWT), Xinjiang, China, the 0.6/0.9-m Schmidt telescope at Xinglong, Hebei, China, and the 1-m telescope at Xuyi, Jiangsu, China. The Nanshan 1-m has a FOV of 1.3x1.3 deg^2, and covered the position of ATLAS17aeu (Tonry et al. GCN 20382), the potential optical afterglow of GRB 170105A (e.g., Marcinkowski et al., GCN 20387; Sharma et al., GCN 20389; Kasliwal, et al., GCN 20393), in a single night. We obtained an upper limit of m(V)>20.0 mag (3 sigma) at 14:55 UT on 2017-01-07. The 0.6/0.9-m Schmidt telescope has a FOV of 1.5x1.5 deg^2, and covered the position of ATLAS17aeu also in a single night. We obtained an upper limit of m(White)>18.8 mag (5 sigma) at 18:26 UT on 2017-01-08. The Xuyi 1-m has a FOV of 3.0x3.0 deg^2, and covered the position of ATLAS17aeu in a single night. We obtained an upper limit of m(r)>14 mag (3 sigma) at 14:32 UT on 2017-01-09. In addition, we note that the two sources, dubbed EWE001 and EWE002, in GCN 20394, are obviously known sources in several surveys such as DSS II and SDSS. -- N: Jinzhong Liu, Dr. O: Main building, 213 P: 150, Science 1-Street, Urumqi, Xinjiang 830011, China T: 86 991 3689027 D: 2012-07-14 E: optics@xao.ac.cn