Discerning internal conditions of pulsating hot subdwarf B stars. Modelling multiple trapped modes in KIC 10001893

Abstract

The frequencies of gravity mode oscillations are determined by the chemical, thermal, and structural properties of stellar interiors, facilitating the study of internal mixing mechanisms in stars. We investigate the impact of discontinuities in the chemical composition induced by the formation of an adiabatic semiconvection region during the core helium (He)-burning phase of evolution of hot subdwarf B-type (sdB) stars. We scrutinize the asteroseismic attributes of the evolutionary stages and assess the core He-burning phase by evaluating the parameter linked to the average interval between the deep trapped modes in both sdB evolutionary models and the observations of KIC 10001893. We perform evolutionary and asteroseismic analyses of sdB stars using MESA and GYRE to examine the properties of the semiconvection region. We address the challenges of relying solely on average interval between oscillation mode periods with consecutive radial orders to identify the core He-burning stage. To enhance identification, we propose a new parameter representing the average interval between deep trapped modes during some of the stages of sdB evolutionary models. Additionally, our results show that integrating convective penetration with convective premixing improves our models and yields comparable outcomes without the need for additional model parameters. Our results can advance the development of detailed evolutionary models for sdB stars by refining internal mixing schemes, enhancing the accuracy of pulsation predictions, and improving alignment with observational data.

arXiv commentAccepted for publication in Astronomy & Astrophysics (A&A), 11 pages, 13 figures

References in corpus (42)

• The chemical composition of the Sun
• Modules for Experiments in Stellar Astrophysics (MESA)
• Modules for Experiments in Stellar Astrophysics (MESA): Giant Planets, Oscillations, Rotation, and Massive Stars
• Modules for Experiments in Stellar Astrophysics (MESA): Binaries, Pulsations, and Explosions
• Low Temperature Opacities
• The Origin of Subdwarf B Star (I): the Formation Channels
• The origin of sdB stars (II)
• Shell-model calculations of stellar weak interaction rates: II. Weak rates for nuclei in the mass range A=45-65 in supernovae environment
• Modules for Experiments in Stellar Astrophysics (MESA): Time-Dependent Convection, Energy Conservation, Automatic Differentiation, and Infrastructure
• GYRE: An open-source stellar oscillation code based on a new Magnus Multiple Shooting Scheme
• Updated Electron-Conduction Opacities: The Impact on Low-Mass Stellar Models
• The Potential of Asteroseismology for Hot, Subdwarf B Stars: A New Class of Pulsating Stars?
• Probing the properties of convective cores through g modes: high-order g modes in SPB and gamma Doradus stars
• Thermodynamic functions of dense plasmas: analytic approximations for astrophysical applications
• Angular momentum transport by heat-driven g-modes in slowly pulsating B stars
• Coulomb tunneling for fusion reactions in dense matter: Path integral Monte Carlo versus mean field
• HS0702+6043: A star showing both short-period p-mode and long-period g-mode oscillations
• Uncertainties on near-core mixing in red-clump stars: effects on the period spacing and on the luminosity of the AGB bump
• Slowing down atomic diffusion in subdwarf B stars: mass loss or turbulence?
• Gravity-mode pulsations in subdwarf B stars: a critical test of stellar opacity
• First Kepler results on compact pulsators VI. Targets in the final half of the survey phase
• First Kepler results on compact pulsators VIII: Mode identifications via period spacings in $g-$mode pulsating Subdwarf B stars
• A hot subdwarf-white dwarf super-Chandrasekhar candidate supernova Ia progenitor
• Acoustic Signatures of the Helium Core Flash
• The treatment of mixing in core helium burning models -- II. Constraints from cluster star counts
• Asteroseismology revealing trapped modes in KIC 10553698A
• Fe-bump instability: the excitation of pulsations in subdwarf B and other low-mass stars
• A seismic approach to testing different formation channels of subdwarf B stars
• Kepler detection of a new extreme planetary system orbiting the subdwarf-B pulsator KIC10001893
• Stellar convective penetration: parameterized theory and dynamical simulations
• An evolutionary study of the pulsating subdwarf B eclipsing binary PG1336-018 (NY Vir)
• The treatment of mixing in core helium burning models -- III. Suppressing core breathing pulses with a new constraint on overshoot
• Evolutionary modelling of subdwarf B stars using MESA with the predictive mixing and convective premixing schemes
• TESS first look at evolved compact pulsators : Discovery and asteroseismic probing of the g-mode hot B subdwarf pulsator EC 21494-7018
• Impact of helium diffusion and helium-flash-induced carbon production on gravity-mode pulsations in subdwarf B stars
• 3D hydrodynamic simulations of massive main-sequence stars. I. Dynamics and mixing of convection and internal gravity waves
• Gravitational settling in pulsating subdwarf B stars and their progenitors
• Asteroseismic analysis of variable hot subdwarf stars observed with TESS I. The mean g-mode period spacings in hot subdwarf B stars
• The blue-edge problem of the V1093 Her instability strip revisited using evolutionary models with atomic diffusion
• The effects of near-core convective shells on the gravity modes of the subdwarf B pulsator KIC 10553698A
• KIC 10001893: A pulsating sdB star with multiple trapped modes
• The theoretical pulsation spectra of hot B subdwarfs. Static and evolutionary STELUM models