Solar-like oscillations in the G8 V star tau Ceti

TL;DR

This study detected and analyzed solar-like oscillations in the G8 V star tau Ceti using HARPS, revealing its oscillation properties and estimating its mass with high precision despite instrumental noise.

Contribution

First detection of solar-like oscillations in tau Ceti, providing detailed mode identification and precise stellar parameter estimation.

Findings

Tau Ceti oscillates with about half the amplitude of the Sun.

Mode lifetime is slightly shorter than solar.

Estimated stellar mass is 0.783 +/- 0.012 solar masses.

Abstract

We used HARPS to measure oscillations in the low-mass star tau Cet. Although the data were compromised by instrumental noise, we have been able to extract the main features of the oscillations. We found tau Cet to oscillate with an amplitude that is about half that of the Sun, and with a mode lifetime that is slightly shorter than solar. The large frequency separation is 169 muHz, and we have identified modes with degrees 0, 1, 2, and 3. We used the frequencies to estimate the mean density of the star to an accuracy of 0.45% which, combined with the interferometric radius, gives a mass of 0.783 +/- 0.012 M_sun (1.6%).