Reinvestigating $\alpha$ Cen AB in light of asteroseismic forward and inverse methods

Abstract

The $\alpha$ Cen stellar system is the closest neighbour to our Sun. Its main component is a binary composed of two main-sequence stars, one more massive than the Sun and one less massive. The system's bright magnitude led to a wealth of astronomical observations over a long period, making it an appealing testbed for stellar physics. In particular, detection of stellar pulsations in both $\alpha$ Cen A and B has revealed the potential of asteroseismology for determining its fundamental stellar parameters. Asteroseismic studies have also focused on the presence of a convective core in the A component, but as yet without definitive confirmation. Progress in the determination of solar surface abundances and stellar opacities have yielded new input for stellar theoretical models. We investigate their impact on a reference system such as $\alpha$ Cen AB. We seek to confirm the presence of a convective core in $\alpha$ Cen A by analysing the role of different stellar physics and the potential of asteroseismic inverse methods. We present a new series of asteroseismic calibrations carried out using forward approach modelling and including updated chemical mixture and opacities in the models. We then complement our analysis with help of recent asteroseismic diagnostic tools based on inverse methods developed for solar-like stars. The inclusion of an updated chemical mixture -- that is less metal-rich -- appears to reduce the predicted asteroseismic masses of each component. Neither classical asteroseismic indicators such as frequency ratios, nor asteroseismic inversions favour the presence of a convective core in $\alpha$ Cen A. The quality of the observational seismic dataset is the main limiting factor to settle the issue. Implementing new observing strategies to improve the precision on the pulsation frequencies would certainly refine the outcome of asteroseismology for this binary system.

arXiv comment16 pages, 8 figures, accepted for publication in Astronomy and Astrophysics

References in corpus (59)

• The chemical composition of the Sun
• Low Temperature Opacities
• Astrophysics Source Code Library
• Solar Chemical Abundances Determined with a CO5BOLD 3D Model Atmosphere
• Solar fusion cross sections II: the pp chain and CNO cycles
• Element Diffusion in the Solar Interior
• Asteroseismology of Solar-Type and Red-Giant Stars
• Helioseismology and Solar Abundances
• Ages and fundamental properties of Kepler exoplanet host stars from asteroseismology
• NACRE II: an update of the NACRE compilation of charged-particle-induced thermonuclear reaction rates for nuclei with mass number $A<16$
• Correcting stellar oscillation frequencies for near-surface effects
• Helioseismological Implications of Recent Solar Abundance Determinations
• Proxima's orbit around Alpha Centauri
• Standing on the shoulders of Dwarfs: the $Kepler$ asteroseismic LEGACY sample I - oscillation mode parameters
• CLES, Code Liegeois d'Evolution Stellaire
• Solar-like oscillations in alpha Centauri B
• A new correction of stellar oscillation frequencies for near-surface effects
• A New Generation of Los Alamos Opacity Tables
• Asteroseismology of the solar analogs 16 Cyg A & B from Kepler observations
• Ghost in the time series: no planet for Alpha Cen B
• Constraining fundamental stellar parameters using seismology. Application to Alpha Centauri AB
• Asteroseismology for "à la carte" stellar age-dating and weighing: Age and mass of the CoRoT exoplanet host HD 52265
• The diameters of Alpha Centauri A and B - A comparison of the asteroseismic and VINCI/VLTI views
• Constraining the difference in convective blueshift between the components of alpha Cen with precise radial velocities
• P-mode observations on Alpha Cen A
• Oscillation frequencies and mode lifetimes in alpha Centauri A
• The acoustic spectrum of alpha Cen A
• The Liege Oscillation Code
• Asteroseismology and calibration of alpha Cen binary system
• Radial Velocity Detection of Earth-mass Planets in the Presence of Activity Noise: The Case of Alpha Centauri Bb
• Ultra-high-precision velocity measurements of oscillations in alpha Cen A
• Analysis of alpha Centauri AB including seismic constraints
• Surface-effect corrections for solar-like oscillations using 3D hydrodynamical simulations
• Calculating the Habitable Zone of Binary Star Systems I: S-Type Binaries
• Asteroseismology of alpha Cen A. Evidence of rotational splitting
• The radii and limb darkenings of Alpha Centauri A and B - Interferometric measurements with VLTI/PIONIER
• Frequency, splitting, linewidth and amplitude estimates of low-l p modes of alpha Cen A: analysis of WIRE photometry
• The Alpha Centauri Binary System: Atmospheric Parameters and Element Abundances
• Classically and Asteroseismically constrained 1D Stellar Evolution Models of $\alpha$ Centauri A and B using Empirical Mixing Length Calibrations
• A Bayesian approach to the modelling of alpha Cen A
• Models of alpha Centauri A and B with and without seismic constraints: time dependence of the mixing-length parameter
• Estimating stellar mean density through seismic inversions
• A new seismic analysis of Alpha Centauri
• On the uncertain nature of the core of $\mathbf{\alpha }$ Cen A
• Close stellar conjunctions of alpha Centauri A and B until 2050 - An mK = 7.8 star may enter the Einstein ring of alpha Cen A in 2028
• Long-Term Stability of Planets in the $\alpha$ Centauri System
• Parallax and masses of alpha Centauri revisited
• Hubble Space Telescope search for the transit of the Earth-mass exoplanet Alpha Centauri Bb
• Core properties of alpha Cen A using asteroseismology
• A search for solar-like oscillations and granulation in alpha Cen A
• Stellar acoustic radii, mean densities and ages from seismic inversion techniques
• In-depth study of 16CygB using inversion techniques
• Constraints on the structure of 16 Cyg A and 16 Cyg B using inversion techniques
• First solar models with OPAS opacity tables
• The chemical composition of $\alpha$ Cen AB revisited
• On the structure of the Sun and alpha Centauri A and B in the light of seismic and non-seismic constraints
• Constraining convective regions with asteroseismic linear structural inversions
• $\alpha$ Centauri A as a potential stellar model calibrator: establishing the nature of its core
• On the nature of the core of $\alpha$ Centauri A: the impact of the metallicity mixture

Cited by in corpus (41)

• Stellar and substellar companions from Gaia EDR3 -- Proper motion anomaly and resolved common proper motion pairs
• A resonant sextuplet of sub-Neptunes transiting the bright star HD 110067
• A pair of Sub-Neptunes transiting the bright K-dwarf TOI-1064 characterised with CHEOPS
• Detection of the tidal deformation of WASP-103b at $3\sigma$ with CHEOPS
• Uncovering the true periods of the young sub-Neptunes orbiting TOI-2076
• Investigating the architecture and internal structure of the TOI-561 system planets with CHEOPS, HARPS-N and TESS
• The geometric albedo of the hot Jupiter HD 189733b measured with CHEOPS
• The EBLM project -- VIII. First results for M-dwarf mass, radius and effective temperature measurements using CHEOPS light curves
• TOI-836: A super-Earth and mini-Neptune transiting a nearby K-dwarf
• The stable climate of KELT-9b
• Connecting photometric and spectroscopic granulation signals with CHEOPS and ESPRESSO
• The phase curve and the geometric albedo of WASP-43b measured with CHEOPS, TESS and HST WFC3/UVIS
• TOI-5678 b: A 48-day transiting Neptune-mass planet characterized with CHEOPS and HARPS
• CHEOPS finds KELT-1b darker than expected in visible light: Discrepancy between the CHEOPS and TESS eclipse depths
• Kepler-93: a testbed for detailed seismic modelling and orbital evolution of super-earths around solar-like stars
• The HD 93963 A transiting system: A 1.04d super-Earth and a 3.65 d sub-Neptune discovered by TESS and CHEOPS
• A full transit of ${\nu }^2$ Lupi d and the search for an exomoon in its Hill sphere with CHEOPS
• Characterisation of the Warm-Jupiter TOI-1130 system with CHEOPS and photo-dynamical approach
• A CHEOPS-enhanced view of the HD3167 system
• Refined parameters of the HD 22946 planetary system and the true orbital period of planet d
• TESS and CHEOPS Discover Two Warm Sub-Neptunes Transiting the Bright K-dwarf HD 15906
• Refining the properties of the TOI-178 system with CHEOPS and TESS
• TOI-1055 b: Neptunian planet characterised with HARPS, TESS, and CHEOPS
• Characterization of the HD 108236 system with CHEOPS and TESS. Confirmation of a fifth transiting planet
• Dark skies of the slightly eccentric WASP-18 b from its optical-to-infrared dayside emission
• Discovery of TOI-1260d and the characterisation of the multi-planet system
• Precise characterisation of HD 15337 with CHEOPS: a laboratory for planet formation and evolution
• Searching for Hot Water World Candidates with CHEOPS: Refining the radii and analysing the internal structures and atmospheric lifetimes of TOI-238 b and TOI-1685 b
• An extended low-density atmosphere around the Jupiter-sized planet WASP-193 b
• The stellar activity-rotation-age relationship under the lens of asteroseismology
• Influence of the magnetic activity cycle on mean density and acoustic radius inversions
• An Updated Line List for Spectroscopic Investigation of G Stars II: Refined Solar Abundances via Extended Wavelength Coverage to 10 000 Å
• A joint effort to discover and characterize two resonant mini Neptunes around TOI-1803 with TESS, HARPS-N and CHEOPS
• Detection and characterisation of a 106-day transiting Jupiter : TOI-2449 b / NGTS-36 b
• Transit Timing Variations in HIP 41378: CHEOPS and TESS confirm a non-transiting sixth planet in the system
• Asteroseismic modelling of main-sequence solar-like stars and Kepler exoplanet host stars with the FICO procedure I. Catalogue of fundamental stellar properties
• CHEOPS observations confirm nodal precession in the WASP-33 system
• The multi-planet system TOI-5624: Four transiting sub-Neptunes with an outer companion revealed by transit-timing variations
• The CHEOPS view of HD 95338b: refined transit parameters, and a search for exomoons
• Gas-depleted planet formation occurred in the four-planet system around the red dwarf LHS 1903
• Improved characterization of the TOI-2141 system: a dense sub-Neptune with non-transiting inner and outer companions