Nonradial pulsations in epsilon Persei

We consider the question of whether all the modes detected in the line prof ile variations of epsilon Persei are consistent with nonradial pulsations e xcited by the kappa mechanism at the opacity Z-bump. We have computed massi ve (12.5-14 M-.) main-sequence models, adjusting the parameters such that t he evolutionary tracks pass around the approximate position of epsilon Per on the H-R diagram. A linear nonadiabatic, nonradial pulsation analysis is applied to these models. The periods in the frame corotating with the stell ar surface for the observed 2.3-4.5 hr modes are found to be consistent wit h the Z-bump kappa mechanism. We have found, however, that the longest-peri od mode (8.48 hr in the observer's frame) cannot be explained by the kappa mechanism. We have examined the effect of rotation on the stability of osci llations and found that the stabilizing effect is weak, so that only a few of the shortest-period modes are stabilized for the rotation speed of epsil on Per. No significant difference is found between prograde and retrograde modes in the stability. It is a puzzle why no retrograde mode has been dete cted in epsilon Per, which should equally be excited by the kappa mechanism . We also discuss the observed and theoretical line profile variations of e psilon Per in the Appendix.