TITLE: GCN CIRCULAR NUMBER: 33177 SUBJECT: GRB 230116D: Nanshan/NEXT optical afterglow detection DATE: 23/01/16 22:26:11 GMT FROM: Dong Xu at NAOC/CAS Z.P. Zhu (NAOC, HUST), D. Xu, S.Q. Jiang, S.Y. Fu, X. Liu, T.H. Lu (NAOC), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report: We observed the field of GRB 230116B detected by Swift (Sonbas et al., GCN 33176) using the NEXT-0.6m telescope located at Nanshan, Xinjiang, China. Observations started at 21:06:37 UT on 2023-01-16, i.e., 114 s after the Swift/BAT trigger. A series of frames in the Sloan r- and z- filters were obtained. An uncatalogued and decaying optical transient is detected at the Swift/XRT position (Sonbas et al., GCN 33176) at coordinates R.A. (J2000) = 6:34:28.21 Dec. (J2000) = +49:52:20.38 with a positional uncertainty of ~0.3 arcsec and r ~ 19.1 mag at ~189 s after the BAT trigger. We thus conclude that the transient is the afterglow of the burst.