Orbital integration and mean separation between member OCs and the OC group center over time. Panels a–b: orbital trajectories in the X−Y and in Z-coordinate over time. Colors are used to distinguish different OCs. Cross symbols mark the present-day locations, triangles represent the past positions of each OC at the birth time of the oldest OC, and diamond symbols denote the predicted positions in 100 Myr. Panel c: the vertical dashed line marks the moment when the separation reaches a minimum.