Overview of semi-sinusoidal stellar variability with the CoRoT satellite

TL;DR

This study analyzes semi-sinusoidal light curves from the CoRoT satellite, revealing evolutionary trends in stellar variability periods and identifying Sun-like candidates, with findings influenced by reddening corrections.

Contribution

It provides a comprehensive overview of semi-sinusoidal stellar variability observed by CoRoT, including period analysis and potential stellar rotation implications.

Findings

Variability periods increase with stellar evolution.

Identified three Sun-like star candidates based on photometric periods.

Period-color behavior depends heavily on reddening correction.

Abstract

To date, the CoRoT space mission has produced more than 124,471 light curves. Classifying these curves in terms of unambiguous variability behavior is mandatory for obtaining an unbiased statistical view on their controlling root-causes. The present study provides an overview of semi-sinusoidal light curves observed by the CoRoT exo-field CCDs. We selected a sample of 4,206 light curves presenting well-defined semi-sinusoidal signatures. The variability periods were computed based on Lomb-Scargle periodograms, harmonic fits, and visual inspection. Color-period diagrams for the present sample show the trend of an increase of the variability periods as long as the stars evolve. This evolutionary behavior is also noticed when comparing the period distribution in the Galactic center and anti-center directions. These aspects indicate a compatibility with stellar rotation, although more information is needed to confirm their root-causes. Considering this possibility, we identified a subset of three Sun-like candidates by their photometric period. Finally, the variability period versus color diagram behavior was found to be highly dependent on the reddening correction.