On the chromospheric activity of stars with planets

TL;DR

This study investigates whether star-planet interactions influence stellar chromospheric activity by analyzing CaII emission fluxes, finding no significant correlation between planetary parameters and chromospheric activity levels in stars with planets.

Contribution

It provides observational constraints showing that star-planet interactions do not significantly affect chromospheric activity in stars with planets.

Findings

No significant correlation between log(R'HK) and planetary parameters.

Chromospheric activity distribution is similar for stars with and without planets.

Star-planet interactions do not have a major effect on stellar chromospheric activity.

Abstract

Context. Signatures of chromospheric activity enhancement have been found for a dozen stars, pointing to a possible star-planet interaction. Nevertheless in the coronal activity regime, there is no conclusive observational evidence for such an interaction. Does star-planet interaction manifest itself only for a few particular cases, without having a major effect on stars with planets in general? Aims. We aim to add additional observational constraints to support or reject the major effects of star-planet interactions in stellar activity, based on CaII chromospheric emission flux. Methods. We performed a statistical analysis of CaII emission flux of stars with planets, as well as a comparison between CaII and X-ray emission fluxes, searching for dependencies on planetary parameters. Results. In the present sample of stars with planets, there are no significant correlations between chromospheric activity indicator log(R'HK) and planetary parameters. Further, the distribution of the chromospheric activity indicator for stars without planets is not distinguishable from the one with planets.