Asteroseismic determination of the stellar rotation period of the Kepler transiting planetary systems and its implications for the spin-orbit architecture

Abstract

We measure the rotation periods of 19 stars in the {\it Kepler} transiting planetary systems, $P_{\mathrm{rot},\mathrm{astero}}$ from asteroseismology and $P_{\mathrm{rot},\mathrm{phot}}$ from photometric variation of their lightcurve. Two stars exhibit two clear peaks in the Lomb-Scargle periodogram, neither of which agrees with the seismic rotation period. Other four systems do not show any clear peak, whose stellar rotation period is impossible to estimate reliably from the photometric variation; their stellar equators may be significantly inclined with respect to the planetary orbital plane. For the remaining 13 systems, $P_{\mathrm{rot},\mathrm{astero}}$ and $P_{\mathrm{rot},\mathrm{phot}}$ agree within 30\%. Interestingly, three out of the 13 systems are in the spin-orbit resonant state in which $P_{\mathrm{orb},\mathrm{b}}/P_{\mathrm{rot},\mathrm{astero}}\approx 1$ with $P_{\mathrm{orb},\mathrm{b}}$ being the orbital period of the inner-most planet of each system. The corresponding chance probability is ($0.2$-$4.7$) \% based on the photometric rotation period data for 464 {\it Kepler} transiting planetary systems. While further analysis of stars with reliable rotation periods is required to examine the statistical significance, the spin-orbit resonance between the star and planets, if confirmed, have important implications for the star-planet tidal interaction, in addition to the origin of the spin-orbit (mis-)alignment of transiting planetary systems.

25 pages, 14 figures, 3 tables, accepted for publication in AJ

References in corpus (7)

• Formation of Hot Planets by a combination of planet scattering, tidal circularization, and Kozai mechanism
• Inferring probabilistic stellar rotation periods using Gaussian processes
• Photometric Amplitude Distribution of Stellar Rotation of Kepler KOIs-Indication for Spin-Orbit Alignment of Cool Stars and High Obliquity for Hot Stars
• Tidal Synchronization and Differential Rotation of Kepler Eclipsing Binaries
• Determination of Three-dimensional Spin-orbit Angle with Joint Analysis of Asteroseismology, Transit Lightcurve, and the Rossiter-McLaughlin Effect: Cases of HAT-P-7 and Kepler-25
• Outer-planet scattering can gently tilt an inner planetary system
• The misaligned orbit of the Earth-sized planet Kepler-408b

Cited by in corpus (4)

• Inferring the Rotation Period Distribution of Stars from their Projected Rotation Velocities and Radii: Application to late-F/early-G Kepler Stars
• Kepler-93: a testbed for detailed seismic modelling and orbital evolution of super-earths around solar-like stars
• Search for Alignment of Disk Orientations in Nearby Star-Forming Regions: Lupus, Taurus, Upper Scorpius, $\rho$ Ophiuchi, and Orion
• Meta-analysis of photometric and asteroseismic measurements of stellar rotation periods: the Lomb-Scargle periodogram, autocorrelation function, wavelet and rotational splitting analysis for 92 Kepler asteroseismic targets