The Contour Method: a new approach to finding modes of non-adiabatic stellar pulsations

Abstract

The contour method is a new approach to calculating the non-adiabatic pulsation frequencies of stars. These frequencies can be found by solving for the complex roots of a characteristic equation constructed from the linear non-adiabatic stellar pulsation equations. A complex-root solver requires an initial trial frequency for each non adiabatic root. A standard method for obtaining initial trial frequencies is to use a star's adiabatic pulsation frequencies, but this method can fail to converge to non-adiabatic roots, especially as the growth and/or damping rate of the pulsations becomes large. The contour method provides an alternative way for obtaining initial trial frequencies that robustly converges to non-adiabatic roots, even for stellar models with extremely non-adiabatic pulsations and thus large growth/damping rates. We describe the contour method implemented in the GYRE stellar pulsation code and use it to calculate the non-adiabatic pulsation frequencies of $10{\mathrm{M}}_{\odot }$ and $20{\mathrm{M}}_{\odot }$ $\beta$ Cephei star models, and of a $0.9{\mathrm{M}}_{\odot }$ extreme helium star model.

12 pages, 14 figures, Accepted to ApJ

References in corpus (3)

• Modules for Experiments in Stellar Astrophysics (MESA)
• Modules for Experiments in Stellar Astrophysics (MESA): Pulsating Variable Stars, Rotation, Convective Boundaries, and Energy Conservation
• Angular momentum transport by heat-driven g-modes in slowly pulsating B stars

Cited by in corpus (14)

• Asteroseismic inference of the near-core magnetic field strength in the main sequence B star HD 43317
• gyre_tides: Modeling binary tides within the gyre stellar oscillation code
• Internal rotation and inclinations of slowly pulsating B stars: Evidence of interior angular momentum transport
• An 18.9-minute Blue Large-Amplitude Pulsator Crossing the 'Hertzsprung Gap' of Hot Subdwarfs
• Tidally Tilted Pulsations in HD 265435, a subdwarf B Star with a Close White Dwarf Companion
• Red Horizontal Branch stars: an asteroseismic perspective
• The imprint of star formation on stellar pulsations
• Two-dimensional simulations of internal gravity waves in a 5 $M_{\odot }$ Zero-Age-Main-Sequence model
• Stochastic excitation of internal gravity waves in rotating late F-type stars: A 3D simulation approach
• Precise Evolutionary Asteroseismology of High-Amplitude δ Scuti Star AE Ursae Majoris
• Stability and pulsation of the first dark stars
• Asteroseismology of low-mass stars: the balance between partial ionisation and Coulomb interactions
• On the diversity of mixing and helium core masses of B-type dwarfs from gravity-mode asteroseismology
• Viscous and centrifugal instabilities of massive stars