Abstract
The Sco OB2 complex is a member of the Local Association. The association contains pre–main-sequence stars in addition to objects some 3 × 107 yr old. If it is assumed that stars in wide binaries are coeval, then the He-weak variables in the supercluster are pre–main-sequence, elevated above that sequence by an amount similar to that of the 3 × 107 yr old, normal stars but contracting toward the sequence, not evolving from it. The apparent great depth of the association is probably a result of some foreground supercluster members, superposed on Sco OB2, and a rift in the absorption cloud between Scorpius and Ophiuchus. The adjoining Chamaeleon complex also appears to be a member of the supercluster.
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