TITLE: GCN CIRCULAR NUMBER: 33616 SUBJECT: GRB 230414B: Nanshan/HMT optical afterglow detection DATE: 23/04/14 17:26:09 GMT FROM: Dong Xu at NAOC/CAS T.H. Lu (NAOC), Z.P. Zhu (NAOC, HUST), S.Y. Fu, S.Q. Jiang, X. Liu, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report: We observed the field of GRB 230414B detected by Swift (A. D'Ai et al., GCN 33612) using the HMT-0.5m telescope located at Nanshan, Xinjiang, China. Observations started at 16:19:34 UT on 2023-04-14, i.e., 313s after the Swift/BAT trigger, and a series of 20 s, 40 s, 60 s, 90 s exposures have been obtained without any filter. Observations are still ongoing. We detected an uncatalogued and varying optical transient (OT) at coordinates R.A. (J2000) = 12:04:22.70 Dec.(J2000) = +53:09:16.38 with an uncertainty of ~ 0.5 arcsec, and it has m(r) ~19.3 mag in the co-added image from the initial exposures, calibrated with the nearby PanSTAR field in the Sloan r-filter. We thus think that the OT is the optical afterglow of the burst.