Convective Instability of Hydrogen-Burning Shells in β-Cephei Stars

It appears that the relative number of β-Cephei variables among the early B stars is comparable to the fraction of the evolutionary lifetime spent in the secondary contraction and early shell-burning phases (Lesh and Aizenman 1973a) and it may therefore be of some interest to investigate possible instability mechanisms associated with hydrogen shell-burning in stars within the mass range of 10 to 15 M _⊙ (Lesh and Aizenman 1973b).