Solar-like Oscillations in the Metal-poor Subgiant ν Indi: Constraining the Mass and Age Using Asteroseismology

Asteroseismology is a powerful method for determining fundamental properties of stars. We report the first application to a metal-poor object, namely the subgiant star ν Ind. We measured precise velocities from two sites, allowing us to detect oscillations and infer a large frequency separation of Δν=24.25+/-0.25 μHz. Combining this value with the location of the star in the H-R diagram and comparing with standard evolutionary models, we were able to place constraints on the stellar parameters. In particular, our results indicate that ν Ind has a low mass (0.85+/-0.04 M_solar) and is at least 9 Gyr old.