2025AJ....169..326L

In this study, we develop a membership identification method and apply it for 30 open clusters (OCs) within 200 pc of the Sun using astrometric data of Gaia DR3. By accounting for projection effects that distort apparent stellar motions, our approach converts astrometric data into accurate five-dimensional positions and velocities. This approach enables better identification of members in nearby OCs. We then compare our refined membership lists with previous catalogs, revealing more members in most OCs, but also the identification of elongated structures in Melotte 25 (Hyades), NGC 2632 (Praesepe), Melotte 111 (Coma Berenices), Platais 3, Melotte 22 (Pleiades), NGC 2451A, Platais 9, IC 2391, Platais 8, UPK 640, and HSC 2986, which we studied in detail. An analysis of the ages of their members reveals that the members within and outside of the tidal radius are distinctly coeval, further validating our methodology. This study suggests that for OCs in the solar neighborhood, correcting for the projection effect is very important for the identification of OC members.