KIC 9451096: Magnetic activity, flares and differential rotation

TL;DR

This study combines spectroscopic and high-precision Kepler photometry to analyze the magnetic activity, flares, and differential rotation of the binary star system KIC 9451096, revealing low magnetic activity and weaker differential rotation compared to the Sun.

Contribution

The paper provides the first detailed analysis of magnetic activity and differential rotation in KIC 9451096 using combined spectroscopic and Kepler data, highlighting its low activity level.

Findings

Detected low-amplitude light variations and flares indicating magnetic activity.

Estimated differential rotation coefficient of the K2V star as 0.069, weaker than the Sun.

Found a low flare activity frequency of 0.000368411 h^{-1}.

Abstract

We present spectroscopic and photometric analysis of KIC\,9451096, where the latter is based on very high precision long cadence photometry obtained by $Kepler$ space craft. Combined spectroscopic and photometric modeling show that the system is a detached eclipsing binary in a circular orbit and composed of F5V + K2V components. Subtracting the best--fit light curve model from whole long cadence data reveals additional low (mmag) amplitude light variation in time and occasional flares, suggesting low, but still remarkable level of magnetic spot activity on the K2V component. Analyzing rotational modulation of light curve residuals enables us to estimate differential rotation coefficient of the K2V component as $k = 0.069 \pm 0.008$, which is 3 times weaker compared with the solar value of $k = 0.19$, assuming a solar type differential rotation. We find stellar flare activity frequency for K2V component as 0.000368411 $h^{-1}$ indicating low magnetic activity level.