Historically in Simbad it was any star towards an association. It does not mean that the star is a member. The membership when available is now put in the hierarchy ...
Historically in Simbad it was any star towards a cluster. It does not mean that the star is a cluster member. The membership when available is now put in the hierarchy ...
Historically in Simbad it was any component of any double system listed in the CCDM or in the WDS catalogues, whatever the separation between the two components, and ...
Historically in Simbad it was any star towards a nebula. It does not mean that the star is inside the nebula. The membership when available is now put in the hierarchy ...