Stellar rotation periods from K2 Campaigns 0-18 -- Evidence for rotation period bimodality and simultaneous variability decrease

Abstract

Rotation period measurements of stars observed with the Kepler mission have revealed a lack of stars at intermediate rotation periods, accompanied by a decrease of photometric variability. Whether this so-called dearth region is a peculiarity of stars in the Kepler field, or reflects a general manifestation of stellar magnetic activity, is still under debate. Our goal is to measure stellar rotation periods and photometric variabilities for tens of thousands of K2 stars, located in different fields along the ecliptic plane, to shed light on the relation between stellar rotation and photometric variability. We use Lomb-Scargle periodograms, auto-correlation and wavelet functions to determine consistent rotation periods. Stellar brightness variability is assessed by computing the variability range from the light curve. We further apply Gaussian mixture models to search for bimodality in the rotation period distribution. Combining measurements from all K2 campaigns, we detect rotation periods in 29,860 stars. For effective temperatures below 6000K, the variability range shows a local minimum at different periods, consistent with an isochrone age of 750 Myr. Additionally, the K2 rotation period distribution shows evidence for bimodality, although the dearth region is less pronounced compared to the Kepler field. The period at the dip of the bimodal distribution shows good agreement with the period at the local variability minimum. We conclude that the period bimodality is present in different fields of the sky, and is hence a general manifestation of stellar magnetic activity. The reduced variability in the dearth region is interpreted as a cancelation between dark spots and bright faculae. Our results strongly advocate that the role of faculae has been underestimated so far, suggesting a more complex dependence of the brightness variability on the rotation period.

14 pages, 13+3 figures

References in corpus (10)

• The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
• The K2 Mission: Characterization and Early results
• Measuring the rotation period distribution of field M-dwarfs with Kepler
• EVEREST: Pixel Level Decorrelation of K2 Light curves
• A Kepler Study of Starspot Lifetimes with Respect to Light Curve Amplitude and Spectral Type
• K2 rotation periods for low-mass Hyads and a quantitative comparison of the distribution of slow rotators in the Hyades and Praesepe
• A Temporary Epoch of Stalled Spin-Down for Low-Mass Stars: Insights from NGC 6811 with Gaia and Kepler
• A path towards understanding the rotation-activity relation of M dwarfs with K2 mission, X-ray and UV data
• Rotation periods and ages of solar analogs and solar twins revealed by the Kepler Mission
• Rotating Stars from Kepler Observed with Gaia DR1

Cited by in corpus (55)

• When Do Stalled Stars Resume Spinning Down? Advancing Gyrochronology with Ruprecht 147
• Surface rotation and photometric activity for Kepler targets. II. G and F main-sequence stars, and cool subgiant stars
• Alone but not lonely: Observational evidence that binary interaction is always required to form hot subdwarf stars
• Stellar Rotation in the Gaia Era: Revised Open Clusters Sequences
• Stellar Rotation in the K2 Sample: Evidence for Modified Spindown
• Recovery of TESS Stellar Rotation Periods Using Deep Learning
• Exploring the evolution of stellar rotation using Galactic kinematics
• TOI-3714 b and TOI-3629 b: Two gas giants transiting M dwarfs confirmed with HPF and NEID
• Further Evidence of Modified Spin-down in Sun-like Stars: Pileups in the Temperature-Period Distribution
• The correlation between photometric variability and radial velocity jitter, based on TESS and HARPS observations
• The SPIRou Legacy Survey Rotation period of quiet M dwarfs from circular polarization in near-infrared spectral lines: I. The SPIRou APERO analysis
• Three K2 Campaigns Yield Rotation Periods for 1013 Stars in Praesepe
• Untangling the Galaxy. IV. Empirical Constraints on Angular Momentum Evolution and Gyrochronology for Young Stars in the Field
• Shallower radius valley around low-mass hosts: Evidence for icy planets, collisions or high-energy radiation scatter
• Detections of solar-like oscillations in dwarfs and subgiants with Kepler DR25 short-cadence data
• The TIME Table: Rotation and Ages of Cool Exoplanet Host Stars
• Stellar Rotation and Structure of the $\alpha$ Persei Complex: When Does Gyrochronology Start to Work?
• The CARMENES search for exoplanets around M dwarfs. Two terrestrial planets orbiting G 264-012 and one terrestrial planet orbiting Gl 393
• A 38 Million Year Old Neptune-Sized Planet in the Kepler Field
• Temporal variation of the photometric magnetic activity for the Sun and Kepler solar-like stars
• Inferring the Rotation Period Distribution of Stars from their Projected Rotation Velocities and Radii: Application to late-F/early-G Kepler Stars
• Detectability of Rotational Modulation in Kepler Sun-like Stars as a Function of Age
• New insights into the rotational evolution of near-solar age stars from the open cluster M67
• Rotation at the Fully Convective Boundary: Insights from Wide WD + MS Binary Systems
• The GAPS programme at TNG XLIV. Projected rotational velocities of 273 exoplanet-host stars observed with HARPS-N
• Statistics of BY Draconis Chromospheric Variable Stars
• Stellar chromospheric activities revealed from the LAMOST-K2 time-domain survey
• Mind the Gap I: H$\alpha$ Activity of M Dwarfs Near the Partially/Fully Convective Boundary and a New H$\alpha$ Emission Deficiency Zone on the Main Sequence
• Multi-campaign Asteroseismic Analysis of eight Solar-like pulsating stars observed by the K2 mission
• Closeby Habitable Exoplanet Survey (CHES). I. Astrometric Noise and Planetary Detection Efficiency due to Stellar Spots and Faculae
• Kepler main-sequence solar-like stars: surface rotation and magnetic-activity evolution
• Wide binaries demonstrate the consistency of rotational evolution between open cluster and field stars
• Periodic stellar variability from almost a million NGTS light curves
• A hot Mars-sized exoplanet transiting an M dwarf
• The breakdown of current gyrochronology as evidenced by old coeval stars
• The Solar Neighborhood LI: A Variability Survey of Nearby M Dwarfs with Planets from Months to Decades with TESS and the CTIO/SMARTS 0.9 m Telescope
• Signature of spin-down stalling in stellar magnetic activity. The case of the open cluster NGC 6811
• The corona -- chromosphere connection studied with simultaneous eROSITA and TIGRE observations
• A Monte Carlo Method for Evaluating Empirical Gyrochronology Models and its Application to Wide Binary Benchmarks
• Photometric activity cycles in fast-rotating stars: Revisiting the reality of stellar activity cycle branches
• The rotation-activity relation of M dwarfs: From K2 to TESS and PLATO
• Unravelling the Period Gap using LAMOST Chromospheric Activity Indices
• Asteroseismic Determination of Stellar Rotation: On Synchronization in the Close Eclipsing Binaries AB Cas and OO Dra
• Four ages of rotating stars in the rotation--activity relationship and gyrochronology
• Rotation and activity in late-type members of the young cluster ASCC 123
• Precise Masses and Orbits for Nine Radial Velocity Exoplanets
• Stellar Characterization and a Chromospheric Activity Analysis of a K2 Sample of Planet-Hosting Stars
• 200,000+ Deep Learning-inferred Periods of Stellar Variability from the All-Sky Automated Survey for Supernovae
• The Solar Neighborhood. LV. M Dwarf Twin Binaries -- One in Five Twin Sibling Pairs Are Mismatched in Activity and/or Rotation
• A Kepler K2 view of subdwarf A-type stars
• The SOL $\text{(Solar Origin and Life)}$ Project: Detailed characterization of candidates for the ZAMS and Subgiant stages
• Activity and Rotation of Nearby Field M Dwarfs in the TESS Southern Continuous Viewing Zone
• Constraints on the Spindown of Fully-Convective M Dwarfs Using Wide Field Binaries
• Rotation of young solar-type stars as seen by Gaia and K2
• SpinSpotter: An Automated Algorithm for Identifying Stellar Rotation Periods With Autocorrelation Analysis