Analysis of alpha Centauri AB including seismic constraints

Abstract

Detailed models of alpha Cen A and B based on new seismological data for alpha Cen B by Carrier & Bourban (2003) have been computed using the Geneva evolution code including atomic diffusion. Taking into account the numerous observational constraints now available for the alpha Cen system, we find a stellar model which is in good agreement with the astrometric, photometric, spectroscopic and asteroseismic data. The global parameters of the alpha Cen system are now firmly constrained to an age of t=6.52+-0.30 Gyr, an initial helium mass fraction Y_i=0.275+-0.010 and an initial metallicity (Z/X)_i=0.0434+-0.0020. Thanks to these numerous observational constraints, we confirm that the mixing-length parameter alpha of the B component is larger than the one of the A component, as already suggested by many authors (Noels et al. 1991, Fernandes & Neuforge 1995 and Guenther & Demarque 2000): alpha_B is about 8% larger than alpha_A (alpha_A=1.83+-0.10 and alpha_B=1.97+-0.10). Moreover, we show that asteroseismic measurements enable to determine the radii of both stars with a very high precision (errors smaller than 0.3%). The radii deduced from seismological data are compatible with the new interferometric results of Kervella et al. (2003) even if they are slightly larger than the interferometric radii (differences smaller than 1%).

13 pages, 9 figures, accepted for publication in A&A

References in corpus (5)

• 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
• The acoustic spectrum of alpha Cen A
• Asteroseismology and calibration of alpha Cen binary system
• A new seismic analysis of Alpha Centauri

Cited by in corpus (57)

• Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics
• TrES-1: The Transiting Planet of a Bright K0V Star
• Proxima's orbit around Alpha Centauri
• Solar-like oscillations in alpha Centauri B
• Dynamical Mass of the Substellar Benchmark Binary HD 130948BC
• Stellar rotation in the Hyades and Praesepe: gyrochronology and braking timescale
• Constraining fundamental stellar parameters using seismology. Application to Alpha Centauri AB
• When Do Stalled Stars Resume Spinning Down? Advancing Gyrochronology with Ruprecht 147
• How Good a Clock is Rotation? The Stellar Rotation-Mass-Age Relationship for Old Field Stars
• Asteroseismology and Interferometry
• Superhabitable Worlds
• The Helium abundance and Delta Y / Delta Z in Lower Main Sequence stars
• The Eclipsing Binary V1061 Cygni: Confronting Stellar Evolution Models for Active and Inactive Solar-Type Stars
• The main-sequence rotation-colour relation in the Coma Berenices open cluster
• New seismological results on the G0 IV eta Bootis
• Asteroseismology of alpha Cen A. Evidence of rotational splitting
• Characterizing solar-type stars from full-length Kepler data sets using the Asteroseismic Modeling Portal
• Absolute dimensions of solar-type eclipsing binaries. II. V636 Centauri: A 1.05 Msun primary with an active, cool, oversize 0.85 Msun secondary
• The Alpha Centauri Binary System: Atmospheric Parameters and Element Abundances
• Investigating the Metallicity-Mixing Length Relation
• Assessing the massive young Sun hypothesis to solve the warm young Earth puzzle
• 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
• X-Ray, FUV, and UV Observations of alpha Centauri B: Determination of Long-term Magnetic Activity Cycle and Rotation Period
• Reinvestigating $\alpha$ Cen AB in light of asteroseismic forward and inverse methods
• Estimating stellar mean density through seismic inversions
• On the uncertain nature of the core of $\mathbf{\alpha }$ Cen A
• Bayesian Asteroseismology of 23 Solar-Like Kepler Targets
• Prospects for asteroseismology
• Models of Procyon A including seismic constraints
• Hubble Space Telescope search for the transit of the Earth-mass exoplanet Alpha Centauri Bb
• Benchmark ages for the Gaia benchmark stars
• Core properties of alpha Cen A using asteroseismology
• Analysis of 70 Ophiuchi AB including seismic constraints
• Asteroseismic Diagnostics of Stellar Convective Cores
• Asteroseismology of the visual binary 70 Ophiuchi
• The Current Status of Asteroseismology
• Modeling beta Virginis using seismological data
• Asteroseismic modelling of the metal-poor star Tau Ceti
• The chemical composition of $\alpha$ Cen AB revisited
• The Mt John University Observatory Search For Earth-mass Planets In The Habitable Zone Of Alpha Centauri
• Was Proxima captured by alpha Centauri A and B?
• New Insights for High-precision Asteroseismology: Acoustic Radius of KIC 6225718
• Seismic constraints on open clusters
• Asteroseismic analysis of solar-mass subgiants KIC 6442183 and KIC 11137075 observed by Kepler
• Asteroseismology of Pulsating Stars
• Current methods for analyzing light curves of solar-like stars
• Coronal X-ray emission and planetary irradiation in HD 209458
• The Solar and $\alpha$ Centauri A and B models improved by opacity enhancement - a possible explanation for the oversize cool stars
• Relevance of the small frequency separation for asteroseismic stellar age, mass, and radius. A statistical investigation for main-sequence low-mass stars
• The frequency separations of stellar p-modes
• Local perturbations of the upper layers of a Sun-like star: the impact on the acoustic oscillation spectrum
• Exploring the small-scale magnetic fields of the solar analog KIC 8006161 using asteroseismology
• Modeling rotating stars in two dimensions
• Lessons for Asteroseismology from White Dwarf Stars
• Searching for Faint Comoving Companions to the $\alpha$ Centauri system in the VVV Survey Infrared Images
• StelNet: Hierarchical Neural Network for Automatic Inference in Stellar Characterization