Radius determination of solar-type stars using asteroseismology: What to expect from the Kepler mission

TL;DR

This study demonstrates that asteroseismology, combined with Kepler data, can accurately determine the radii of solar-type stars to within 3%, significantly improving over traditional methods and aiding exoplanet characterization.

Contribution

The paper shows that stellar radii can be precisely measured using asteroseismic data from Kepler, achieving better accuracy than non-seismic methods, validated through simulation exercises.

Findings

Stellar radii can be determined within 3% accuracy using asteroseismology.

Asteroseismic methods outperform traditional techniques by a factor of 5-10 in radius estimation.

Automatic pipelines can reliably estimate stellar radii for Kepler data.

Abstract

For distant stars, as observed by the NASA Kepler satellite, parallax information is currently of fairly low quality and is not complete. This limits the precision with which the absolute sizes of the stars and their potential transiting planets can be determined by traditional methods. Asteroseismology will be used to aid the radius determination of stars observed during NASA's Kepler mission. We report on the recent asteroFLAG hare-and-hounds Exercise#2, where a group of `hares' simulated data of F-K main-sequence stars that a group of `hounds' sought to analyze, aimed at determining the stellar radii. Based on the asteroseismic large frequency spacing, obtained from simulations of 4-year time series data from the Kepler mission, we demonstrate that the stellar radii can be correctly and precisely determined, when combined with traditional stellar parameters from the Kepler Input Catalogue. The radii found by the various methods used by each independent hound generally agree with the true values of the artificial stars to within 3%, when the large frequency spacing is used. This is 5--10 times better than the results where seismology is not applied. These results give strong confidence that radius estimation can be performed to better than 3% for solar-like stars using automatic pipeline reduction. Even when the stellar distance and luminosity are unknown we can obtain the same level of agreement.