Solar-like oscillations in massive main-sequence stars. I. Asteroseismic signatures of the driving and damping regions

TL;DR

This paper theoretically investigates the excitation of solar-like oscillations in massive main-sequence stars, focusing on the roles of convective regions caused by the iron opacity bump and the convective core, providing insights into their detectability and diagnostic potential.

Contribution

It introduces a comprehensive non-adiabatic computational approach to estimate mode amplitudes driven by different convective regions in massive stars, highlighting their potential to produce observable solar-like oscillations.

Findings

Both convective regions can excite p modes above observational thresholds.

The amplitudes of excited modes can reach solar-like levels.

Potential for asteroseismic diagnostics to identify the responsible convective zone.

Abstract

Motivated by the recent detection of stochastically excited modes in the massive star V1449 Aql (Belkacem et al., 2009b), already known to be a $\beta$ Cephei, we theoretically investigate the driving by turbulent convection. By using a full non-adiabatic computation of the damping rates, together with a computation of the energy injection rates, we provide an estimate of the amplitudes of modes excited by both the convective region induced by the iron opacity bump and the convective core. Despite uncertainties in the dynamical properties of such convective regions, we demonstrate that both are able to efficiently excite $p$ modes above the CoRoT observational threshold and the solar amplitudes. In addition, we emphasise the potential asteroseismic diagnostics provided by each convective region, which we hope will help to identify the one responsible for solar-like oscillations, and to give constraints on this convective zone. A forthcoming work will be dedicated to an extended investigation of the likelihood of solar-like oscillations across the Hertzsprung-Russell diagram.