Uncertainties and biases in modelling 16 Cyg A and B

Abstract

In this study I assess how existing data for the solar analogues 16 Cyg A and B, in particular the asteroseismic measurements obtained from \emph{Kepler}, constrain theoretical stellar models. The goal is two-fold: first to use these stars as benchmarks to discuss which precisions can realistically be expected on the inferred stellar quantities; and second to determine how well 'non-standard' prescriptions, such as microscopic diffusion and overshoot, are constrained. I used a Bayesian statistical model to infer the values of the stellar parameters of 16 Cyg A and B. I sampled the posterior density of the stellar parameters via a Markov chain Monte Carlo (MCMC) algorithm, tested different physical prescription, and examined the impact of using different seismic diagnostics. General good agreement is found with several recent modelling studies on these stars, even though some discrepancies subsist regarding the precise estimates of the uncertainties on the parameters. An age of $6.88\pm 0.12$ Gyr is estimated for the binary system. The inferred masses, $1.07\pm 0.02$ M${}_{\odot }$ for Cyg A and $1.05\pm 0.02$ M${}_{\odot }$ for Cyg B, are shown to be stable with respect to changes in the physical prescriptions considered for the modelling. For both stars, microscopic diffusion has a significant effect on the estimates of the initial metallicity. Overshoot is confined to very small regions below the convective zone. I show that a proper treatment of the seismic constraints is necessary to avoid biases in the estimate of the mass.

arXiv comment13 pages, 7 figures, to appear in A & A

References in corpus (36)

• The chemical composition of the Sun
• Solar Models with Helium and Heavy Element Diffusion
• Helioseismology and Solar Abundances
• ADIPLS -- the Aarhus adiabatic oscillation package
• Correcting stellar oscillation frequencies for near-surface effects
• Standing on the shoulders of Dwarfs: the Kepler asteroseismic LEGACY sample II - radii, masses, and ages
• ASTEC -- the Aarhus STellar Evolution Code
• Solar-like oscillations in alpha Centauri B
• Asteroseismology of the solar analogs 16 Cyg A & B from Kepler observations
• Properties of 42 Solar-type Kepler Targets from the Asteroseismic Modeling Portal
• Stellar ages and convective cores in field main-sequence stars: first asteroseismic application to two Kepler targets
• Global Seismology of the Sun
• Asteroseismology and Interferometry
• P-mode observations on Alpha Cen A
• Evidence for solar-like oscillations in beta Hydri
• Asteroseismology of the planet-hosting star $\mu$ Arae. I. The acoustic spectrum
• Asteroseismic inference on rotation, gyrochronology and planetary system dynamics of 16 Cygni
• Solar-like oscillations in the G2 subgiant beta Hydri from dual-site observations
• A Stellar Model-fitting Pipeline for Asteroseismic Data from the Kepler Mission
• Fundamental Parameters of Main-Sequence Stars in an Instant with Machine Learning
• Asteroseismology of alpha Cen A. Evidence of rotational splitting
• Numerical Simulations of Penetration and Overshoot in the Sun
• Characterizing solar-type stars from full-length Kepler data sets using the Asteroseismic Modeling Portal
• Toward a consistent use of overshooting parametrizations in 1D stellar evolution codes
• The complementary roles of interferometry and asteroseismology in determining the mass of solar-type stars
• Low abundances of heavy elements in the solar outer layers: comparisons of solar models with helioseismic inversions
• The exoplanet-host star iota Horologii: an evaporated member of the primordial Hyades cluster
• Asteroseismic modeling of 16 Cyg A & B using the complete Kepler data set
• A photometric and spectroscopic survey of solar twin stars within 50 parsecs of the Sun: I. Atmospheric parameters and color similarity to the Sun
• On the uncertain nature of the core of $\mathbf{\alpha }$ Cen A
• Model-independent measurement of internal stellar structure in 16 Cygni A and B
• Convective overshooting and penetration in a Boussinesq spherical shell
• Estimating the p-mode frequencies of the solar twin 18 Sco
• Latitudinal differential rotation in the solar analogues 16 Cyg A and B
• Anomalies in the Kepler Asteroseismic Legacy Project Data. A re-analysis of 16 Cyg A&B, KIC8379927 and 6 solar-like stars
• Modelling the solar twin 18 Sco

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• Thorough characterisation of the 16 Cygni system. Part II. Seismic inversions of the internal structure
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• Detecting active latitudes of Sun-like stars using asteroseismic a-coefficients
• Weighing stars from birth to death: mass determination methods across the HRD