B star pulsation - theory and seismological prospects
Abstract
Two distinct types of oscillations are encountered among Main Sequence B stars. In beta Cep stars, occurring in the B0 - B2 range and varying with periods of few hours, the excited modes are p- and/or g-modes of low radial degrees. In SPB stars, which occur in the B4-B8 range, high-order g-modes having periods from one to four days are excited. All these stars owe their oscillations to the opacity driving mechanism acting in the metal-opacity-bump zone. We understand how the detected modes are excited but we do not understand yet the large diversity in the form of their pulsation. For that an essential progress in the nonlinear theory and modeling of multimodal oscillations is needed. The modes excited in these stars probe deep stellar interior and therefore they are of potential interest for testing theory of stellar evolution and rotation. However, attempts made to construct models for two multiperiodic beta Cep revealed primarily problems that must be solved before this application could be implemented. An easier, though still not fully unexplored, application of this type of stars is probing ages and metal abundances of the host stellar systems.
- Publication:
-
New Eyes to See Inside the Sun and Stars
- Pub Date:
- 1998
- Bibcode:
- 1998IAUS..185..355D