The rotation of planet-hosting stars

TL;DR

This study finds that stars hosting planets tend to rotate more slowly than similar stars without detected planets, suggesting a possible link between stellar rotation and planet presence or detection biases.

Contribution

It provides the first statistical comparison of rotation periods between planet-hosting stars and a matched control sample, highlighting a significant difference in rotation rates.

Findings

Planet-hosting stars rotate on average 1.63 days slower.

The rotation difference is statistically significant across different detection methods.

Results suggest potential detection biases or a physical link between rotation and planet formation.

Abstract

Understanding the distribution of angular momentum during the formation of planetary systems is a key topic in astrophysics. Data from the $\textit{Kepler}$ and $\textit{Gaia}$ missions allow to investigate whether stellar rotation is correlated with the presence of planets around Sun-like stars. Here, we perform a statistical analysis of the rotation period of 493 planet-hosting stars. These are matched to a control sample, without detected planets, with similar effective temperatures, masses, radii, metallicities, and ages. We find that planet-hosting stars rotate on average $1.63 \pm 0.40$ days slower. The difference in rotation is statistically significant both in samples including and not including planets confirmed by radial velocity follow-up observations. We also analyse the dependence of rotation distribution on various stellar and planetary properties. Our results could potentially be explained by planet detection biases depending on the rotation period of their host stars in both RV and transit methods. Alternatively, they could point to a physical link between the existence of planets and stellar rotation, emphasising the need to understand the role of angular momentum in the formation and evolution planetary systems.