Current methods for analyzing light curves of solar-like stars

TL;DR

This review discusses current techniques for analyzing light curves of solar-like stars, highlighting methods for determining rotation, granulation, and p-mode characteristics using data from CoRoT and Kepler.

Contribution

It provides a comprehensive overview of the methods used in solar-like star seismology and discusses recent findings and challenges with interpreting light curve data.

Findings

Accurate stellar rotation rates can be derived from light curve magnetic activity.

Power spectra constrain stellar granulation, revealing discrepancies with models.

CoRoT data shows unexpectedly short p-mode lifetimes in F stars.

Abstract

CoRoT has allowed a quantitative leap for the solar-like-star seismology thanks to 5-month-long uninterrupted timeseries of high-precision photometric data. Kepler is also starting to deliver similar data. Now, several F and G main-sequence stars have been analyzed. The techniques developed to interpret light curves directly inherit from the experience got on the Sun with helioseismology. I describe in this review the methods currently used to analyze these light curves. First, these data provide an accurate determination of the stellar rotation rate. This is possible thanks to the magnetic activity of stars. The power spectra of light curves put also constraints on the stellar granulation, which can be directly compared to 3-D stellar atmosphere models; this shows still unexplained discrepancies. I then detailed a standard method for extracting p-mode characteristics (frequency, amplitude and lifetime). CoRoT has revealed unexpected short life times for F stars. Last, I also discuss errors and biases of mode frequencies, especially the ones due to the simplified description of the rotation generally used.