Excitation and visibility of slow modes in rotating B-type stars

Abstract

We use the traditional approximation to describe oscillations with frequencies comparable to the angular rotation rate. Validity of this approximation in application to main-sequence B stars is discussed. Numerical results regarding mode stability and visibility are presented for a model of the Be star HD 163868. For this object, Walker et al.(2005) detected a record number of mode frequencies using data from the small space telescope MOST. Our interpretation of these data differs from that of Walker et al. In particular, we interpret peaks in the lowest frequency range as retrograde g modes. We find instability in a large number of modes that remain undetectable because of unfavourable aspect and/or effect of cancellation. There is no clear preference to excitation of prograde modes.

9 pages, 3 figures, accepted for publication in MNRAS

Cited by in corpus (12)

• Variability of newly identified B-type stars observed by Kepler
• Beta Cephei stars in the ASAS-3 data. II. 103 new Beta Cephei stars and a discussion of low-frequency modes
• MOST detects SPBe pulsations in HD 127756 & HD 217543: Asteroseismic rotation rates independent of vsini
• Angular momentum transport by magnetic fields in main sequence stars with Gamma Doradus pulsators
• Seismic modelling of early B-type pulsators observed by BRITE: I. $\theta$ Ophiuchi
• Seismic modeling of a very young SPB star -- KIC8264293
• A Spectroscopic and Photometric Investigation of the Mercury-Manganese Star KIC 6128830
• Non-radial oscillations of the rapidly rotating Be star HD 163868
• Photometric variability of the Be star CoRoT-ID 102761769
• Oscillation modes in the rapidly rotating Slowly Pulsating B-type star $\bmu$ Eridani
• Revising the evolutionary stage of HD 163899: the effects of convective overshooting and rotation
• Non-linear Three-mode Coupling of Gravity Modes in Rotating Slowly Pulsating B Stars: Stationary Solutions and Modeling Potential