Normalized differential light curve of Proxima Centauri observed using BSST at the Antarctic Zhongshan station during 10 nights from 2016 August 29 to September 21. Time has been converted to HJD from UTC. The average photometry precision is 4.6 mmag. The shaded areas are time within 1σ predicted transit windows (T_IC = 2,457,629.56 ± 0.67, T_IC = 2,457,640.74 ± 0.67 HJD, and T_IC = 2,457,651.93 ± 0.67). The transit ephemeris is derived by Kipping et al. (2017) using the radial velocity solution of Anglada-Escudé et al. (2016). The vertical solid line indicates the midtransit time of the candidate event identified in Section 4.