Stellar Rotation Periods of the Kepler Objects of Interest: A Dearth of Close-in Planets around Fast Rotators

TL;DR

This study analyzes Kepler data to measure stellar rotation periods and finds a significant scarcity of close-in planets around fast-rotating stars, suggesting a possible link between stellar rotation and planet orbital proximity.

Contribution

It provides a large dataset of stellar rotation periods for KOIs and identifies a correlation between slow stellar rotation and the presence of close-in planets.

Findings

Fast rotators lack close-in planets

Slow rotators host short-period planets

Rotation periods were measured for 737 stars

Abstract

We present a large sample of stellar rotation periods for Kepler Objects of Interest (KOIs), based on three years of public Kepler data. These were measured by detecting periodic photometric modulation caused by star spots, using an algorithm based on the autocorrelation function (ACF) of the light curve, developed recently by McQuillan, Aigrain & Mazeh (2013). Of the 1919 main-sequence exoplanet hosts analyzed, robust rotation periods were detected for 737. Comparing the detected stellar periods to the orbital periods of the innermost planet in each system reveals a notable lack of close-in planets around rapid rotators. It appears that only slowly spinning stars, with rotation periods longer than 5-10 days, host planets on orbits shorter than 3 days, although the mechanism(s) that lead(s) to this is not clear.