The Host Stars of Keplers Habitable Exoplanets: Superflares, Rotation and Activity

TL;DR

This study analyzes Kepler's data on Earth-like exoplanet host stars to assess stellar activity, rotation, and superflares, providing insights into planetary habitability and stellar behavior.

Contribution

It presents a comprehensive analysis of stellar activity, rotation, and superflares in Kepler's most Earth-like exoplanet host stars, including the first detection of superflares on Kepler-438.

Findings

Detection of superflares on Kepler-438

Derived stellar rotation periods and activity indices

Implications for planetary atmospheres and habitability

Abstract

We embark on a detailed study of the lightcurves of Keplers most Earth-like exoplanet host stars using the full length of Kepler data. We derive rotation periods, photometric activity indices, flaring energies, mass loss rates, gyrochronological ages, X-ray luminosities and consider implications for the planetary magnetospheres and habitability. Furthermore, we present the detection of superflares in the lightcurve of Kepler-438, the exoplanet with the highest Earth Similarity Index to date. Kepler-438b orbits at a distance of 0.166AU to its host star, and hence may be susceptible to atmospheric stripping. Our sample is taken from the Habitable Exoplanet Catalogue, and consists of the stars Kepler-22, Kepler-61, Kepler-62, Kepler-174, Kepler-186, Kepler-283, Kepler-296, Kepler-298, Kepler-438, Kepler-440, Kepler-442, Kepler-443 and KOI-4427, between them hosting 15 of the most habitable transiting planets known to date from Kepler.