Bayesian Asteroseismology of 23 Solar-Like Kepler Targets

TL;DR

This study performs a Bayesian asteroseismic analysis of 23 Kepler targets, comparing results with previous methods, revealing discrepancies in stellar parameters and uncertainties, and exploring surface effects' dependence on stellar properties.

Contribution

It introduces a consistent Bayesian grid-based approach to asteroseismology and examines the impact of surface effects and model differences on stellar parameter estimation.

Findings

Differences in stellar parameters and uncertainties compared to previous methods.

Surface effect magnitude depends on the mixing length parameter.

Significant surface effects are observed in stars near the Sun's position in the HR diagram.

Abstract

We study 23 previously published Kepler targets to perform a consistent grid-based Bayesian asteroseismic analysis and compare our results to those obtained via the Asteroseismic Modelling Portal (AMP). We find differences in the derived stellar parameters of many targets and their uncertainties. While some of these differences can be attributed to systematic effects between stellar evolutionary models, we show that the different methodologies deliver incompatible uncertainties for some parameters. Using non-adiabatic models and our capability to measure surface effects, we also investigate the dependency of these surface effects on the stellar parameters. Our results suggest a dependence of the magnitude of the surface effect on the mixing length parameter which also, but only minimally, affects the determination of stellar parameters. While some stars in our sample show no surface effect at all, the most significant surface effects are found for stars that are close to the Sun's position in the HR diagram.