Rotation speed and stellar axis inclination from p modes: How CoRoT would see other suns

Abstract

In the context of future space-based asteroseismic missions, we have studied the problem of extracting the rotation speed and the rotation-axis inclination of solar-like stars from the expected data. We have focused on slow rotators (at most twice solar rotation speed), firstly because they constitute the most difficult case and secondly because some of the CoRoT main targets are expected to have slow rotation rates. Our study of the likelihood function has shown a correlation between the estimates of inclination of the rotation axis i and the rotational splitting deltanu of the star. By using the parameters, i and deltanu*=deltanu sin(i), we propose and discuss new fitting strategies. Monte Carlo simulations have shown that we can extract a mean splitting and the rotation-axis inclination down to solar rotation rates. However, at the solar rotation rate we are not able to correctly recover the angle i although we are still able to measure a correct deltanu* with a dispersion less than 40 nHz.