Kepler-411 star activity: connection between starspots and superflares

Abstract

Stellar magnetic activity, just like that of the Sun, manifests itself in the form of flares and spots on the surface of the star. In the solar case, the largest flares originate from large active regions. In this work, we present a study of the activity of the star Kepler-411, including spot modeling from planetary transits. Our goal was to search for a connection between the area of starspots with the energy of superflares produced by this star. Kepler-411 is a K2V-type star with an average rotation period of 10.52 days, radius of 0.79 $R_{\odot }$ and a mass of 0.83 $M_{\odot }$, which was observed by the Kepler satellite for about 600 days. Transit mapping allowed for the characterization of 198 starspots with estimates of their radius and temperature. Kepler-411 starspots had an average radius of $(17\pm 7)\times 10^3$ km and a mean temperature of $3800\pm 700$ K. Visual inspection of the light curves of Kepler-411 yields the identification of 65 superflares. The detected superflares lasted from 8 to 260 min and their energy varied from $10^{33}-10^{35}$ ergs. The power-law index of the flare frequency distribution as a function of energy is (-2.04 $\pm$ 0.13) for the flare on Kepler-411. A positive correlation between the area of starspots and the energy of superflares was found when considering the averages taken every 16 to 35 days, with the highest correlation occurring for averages every 21 days. This timing is probably related to the lifetime of the Kepler-411 spots.

arXiv comment10 pages, 9 figures

References in corpus (29)

• Superflares on Solar Type Stars Observed with Kepler I. Statistical Properties of Superflares
• The Transit Light Source Effect: False Spectral Features and Incorrect Densities for M-dwarf Transiting Planets
• Kepler Flares I. Active and Inactive M dwarfs
• Impact of Space Weather on Climate and Habitability of Terrestrial Type Exoplanets
• Statistical properties of superflares on solar-type stars based on 1-min cadence data
• White-light flares on cool stars in the Kepler Quarter 1 Data
• Do Kepler superflare stars really include slowly-rotating Sun-like stars ? - Results using APO 3.5m telescope spectroscopic observations and Gaia-DR2 data -
• Kepler-63b: A Giant Planet in a Polar Orbit around a Young Sun-like Star
• A White Light Megaflare on the dM4.5e Star YZ CMi
• Influence of Stellar Multiplicity On Planet Formation. I. Evidence of Suppressed Planet Formation Due to Stellar Companions Within 20 AU and Validation of Four Planets From the Kepler Multiple Planet Candidates
• The flare catalog and the flare activity in the Kepler mission
• The Starspots of HAT-P-11: Evidence for a Solar-like Dynamo
• Statistical Properties of Superflares on Solar-type Stars: Results Using All of the Kepler Primary Mission Data
• A Bayesian Approach to Solar Flare Prediction
• Properties of starspots on CoRoT-2
• Time-resolved spectroscopy and photometry of an M dwarf flare star YZ Canis Minoris with OISTER and TESS: Blue asymmetry in H$\alpha$ line during the non-white light flare
• Superflares, chromospheric activities and photometric variabilities of solar-type stars from the second-year observation of TESS and spectra of LAMOST
• Kepler-411: a four-planet system with an active host star
• High Dispersion Spectroscopy of Solar-type Superflare Stars. II. Stellar Rotation, Starspots, and Chromospheric Activities
• Kepler Flares III: Stellar Activity on GJ 1245 A and B
• Superflares and Variability in Solar-Type Stars with $TESS$ in the Southern Hemisphere
• Stellar flares detected with the Next Generation Transit Survey
• From Starspots to Stellar Coronal Mass Ejections -- Revisiting Empirical Stellar Relations
• Kepler Flares IV: A Comprehensive Analysis of the Activity of the dM4e Star GJ 1243
• Activity and rotation of Kepler-17
• Temporal Evolution of Spatially-Resolved Individual Star Spots on a Planet-Hosting Solar-type Star: Kepler 17
• The Connection between Starspots and Flares on Main-Sequence Kepler Stars
• Stellar Magnetic Activity and "Butterfly Diagram" of Kepler-63
• Kepler-411 Differential Rotation from Three Transiting Planets