A precise asteroseismic age and radius for the evolved Sun-like star KIC 11026764

TL;DR

This paper uses Kepler asteroseismic data combined with spectroscopic observations to precisely determine the radius and age of the evolved Sun-like star KIC 11026764, achieving high accuracy and precision.

Contribution

It presents a detailed modeling approach employing multiple codes to accurately derive the star's fundamental properties from combined asteroseismic and spectroscopic data.

Findings

Radius determined with ~1% precision

Age estimated with ~15% accuracy

Multiple independent models agree on stellar parameters

Abstract

The primary science goal of the Kepler Mission is to provide a census of exoplanets in the solar neighborhood, including the identification and characterization of habitable Earth-like planets. The asteroseismic capabilities of the mission are being used to determine precise radii and ages for the target stars from their solar-like oscillations. Chaplin et al. (2010) published observations of three bright G-type stars, which were monitored during the first 33.5 days of science operations. One of these stars, the subgiant KIC 11026764, exhibits a characteristic pattern of oscillation frequencies suggesting that it has evolved significantly. We have derived asteroseismic estimates of the properties of KIC 11026764 from Kepler photometry combined with ground-based spectroscopic data. We present the results of detailed modeling for this star, employing a variety of independent codes and analyses that attempt to match the asteroseismic and spectroscopic constraints simultaneously. We determine both the radius and the age of KIC 11026764 with a precision near 1%, and an accuracy near 2% for the radius and 15% for the age. Continued observations of this star promise to reveal additional oscillation frequencies that will further improve the determination of its fundamental properties.