Starspot activity and differential rotation in KIC 11560447

TL;DR

This study uses Kepler data to analyze starspot activity and differential rotation on a K1-type subgiant in a binary system, revealing solar-like differential rotation and recurrent spot patterns.

Contribution

It introduces a method to measure stellar differential rotation from spot migration patterns and validates starspot reconstruction techniques with simulations.

Findings

Detected solar-like differential rotation in KIC 11560447

Observed recurrent spot activity over the observation period

Identified a trend towards axisymmetric spot distribution

Abstract

Using high-precision photometry from the \textit{Kepler} mission, we investigate patterns of spot activity on the K1-type subgiant component of KIC 11560447, a short-period late-type eclipsing binary. We tested the validity of maximum entropy reconstructions of starspots by numerical simulations. Our procedure successfully captures up to three large spot clusters migrating in longitude. We suggest a way to measure a lower limit for stellar differential rotation, using slopes of spot patterns in the reconstructed time-longitude diagram. We find solar-like differential rotation and recurrent spot activity with a long-term trend towards a dominant axisymmetric spot distribution during the period of observations.