# Activity Analyses for Solar-type Stars Observed with Kepler. II. Magnetic Feature Versus Flare Activity

## TL;DR

This study investigates the relationship between magnetic feature activity and flare activity in three solar-type stars observed with Kepler, revealing that their long-term variations are not always synchronized, unlike the Sun.

## Contribution

It provides new insights into the different source regions of magnetic features and flares in solar-type stars, based on long-term observational data.

## Key findings

- Magnetic feature and flare activities both show long-term variations.
- These activities are not always in phase, unlike the Sun.
- Star KIC 6034120 shows similar cycle lengths for both activities.

## Abstract

The light curves of solar-type stars present both periodic fluctuation and flare spikes. The gradual periodic fluctuation is interpreted as the rotational modulation of magnetic features on the stellar surface and is used to deduce magnetic feature activity properties. The flare spikes in light curves are used to derive flare activity properties. In this paper, we analyze the light curve data of three solar-type stars (KIC 6034120, KIC 3118883, and KIC 10528093) observed with Kepler space telescope and investigate the relationship between their magnetic feature activities and flare activities. The analysis shows that: (1) both the magnetic feature activity and the flare activity exhibit long-term variations as the Sun does; (2) unlike the Sun, the long-term variations of magnetic feature activity and flare activity are not in phase with each other; (3) the analysis of star KIC 6034120 suggests that the long-term variations of magnetic feature activity and flare activity have a similar cycle length. Our analysis and results indicate that the magnetic features that dominate rotational modulation and the flares possibly have different source regions, although they may be influenced by the magnetic field generated through a same dynamo process.