Evolutionary effects on radial pulsations of β-cephei stars

During recent years it has become rather clear that the β -Cephei variables are in a hydrogen-buring stage of their evolution. The 8 ( β -Cephei variables which have been found in the Scorpio-Centaurus association highlights this. The 6 of these variables for which Glaspey (1971) provides ( β , (u – b) 0 ) photometry all fall at the tip of the sequence in the Hertzsprung-Russell diagram. This indicates that ( β -Cephei stars are in the final stages of core hydrogen burning. This is in good agreement with the position of the β -Cephei strip of Watson (1972) in the H-R diagram.