(a) On-sky projection of the updated sample of C-19 stream members. Previously identified members are represented by magenta daggers (Yuan et al. 2022b) and purple crosses (Bonifacio et al. 2024). The solid black line corresponds to the C-19 orbit derived by Ibata et al. (2023), and the small gray dots represent the simulated stream from Errani et al. (2022). Candidates identified from the fusion of StarGO and STREAMFINDER are plotted as orange circles, and the candidates identified using a star-by-star search of photometric metallicity catalogs after Gaia DR3 are plotted as blue circles. All shown members have radial velocities consistent with the orbit, as shown in panel b. Stars that have spectroscopic [Fe/H] < −3.0 are considered as members and are highlighted with solid black circles. The other stars are probable members and highlighted by dotted circles (see text for more details). (c) Color-magnitude diagram of all the C-19 members previously identified or from this study. The gray crosses denote candidate members without radial velocity information (Yuan et al. 2022b). The solid black line here represents the 12-Gyr isochrone with [Fe/H] = −2.2 from the PARSEC model (Bressan et al. 2012; Fu et al. 2018).