Pulsational stability of rotating main sequence stars: the second order effects of rotation on the nonadiabatic oscillations.

We examine the pulsational stability of rotating OB stars. We include the effects of the centifugal force (and hence the rotational equilibrium deformation) as well as those of the Coriolis force to calculate the nonadiabatic oscillations of the rotating stars. The effects of the centrifugal force are the second order effects of rotation, while the Coriolis force is the first order effects of rotation. We show that the second order effects of rotation are not so effective to influence the pulsational stability of the stars. We suggest that the fourth order effects of rotation can be important enough to influence the pulsational stability of the p modes of rapidly rotating OB stars.