On the seismic age and heavy-element abundance of the Sun

TL;DR

This paper presents a seismic calibration method to estimate the Sun's age and heavy-element abundance using low-degree acoustic modes, providing results consistent with recent measurements and applicable to other solar-like stars.

Contribution

It introduces a new seismic calibration technique based on low-degree acoustic modes, applicable to solar-type stars observed by Kepler and SONG, to estimate stellar age and composition.

Findings

Solar age estimated at 4.60±0.04 Gy

Surface heavy-element abundance Zs=0.0142±0.0005

Method applicable to other solar-like stars

Abstract

We estimate the main-sequence age and heavy-element abundance of the Sun by means of an asteroseismic calibration of theoretical solar models using only low-degree acoustic modes from the BiSON. The method can therefore be applied also to other solar-type stars, such as those observed by the NASA satellite Kepler and the planned ground-based Danish-led SONG network. The age, 4.60+/-0.04 Gy, obtained with this new seismic method, is similar to, although somewhat greater than, today's commonly adopted values, and the surface heavy-element abundance by mass, Zs=0.0142+/-0.0005, lies between the values quoted recently by Asplund et al. (2009) and by Caffau et al. (2009). We stress that our best-fitting model is not a seismic model, but a theoretically evolved model of the Sun constructed with `standard' physics and calibrated against helioseismic data.