A Window on Exoplanet Dynamical Histories: Rossiter-McLaughlin Observations of WASP-13b and WASP-32b

Abstract

We present Rossiter-McLaughlin observations of WASP-13b and WASP-32b and determine the sky-projected angle between the normal of the planetary orbit and the stellar rotation axis ($\lambda$). WASP-13b and WASP-32b both have prograde orbits and are consistent with alignment with measured sky-projected angles of $\lambda ={8^{\circ }}_{-12}^{+13}$ and $\lambda ={-2^{\circ }}_{-19}^{+17}$, respectively. Both WASP-13 and WASP-32 have $T_{\mathrm{eff}}<6250$K and therefore these systems support the general trend that aligned planetary systems are preferentially found orbiting cool host stars. A Lomb-Scargle periodogram analysis was carried out on archival SuperWASP data for both systems. A statistically significant stellar rotation period detection (above 99.9\% confidence) was identified for the WASP-32 system with $P_{\mathrm{rot}}=11.6\pm 1.0$ days. This rotation period is in agreement with the predicted stellar rotation period calculated from the stellar radius, $R_{\star }$, and $v\sin i$ if a stellar inclination of $i_{\star }=90^{\circ }$ is assumed. With the determined rotation period, the true 3D angle between the stellar rotation axis and the planetary orbit, $\psi$, was found to be $\psi =11^{\circ }\pm 14$. We conclude with a discussion on the alignment of systems around cool host stars with $T_{\mathrm{eff}}<6150$K by calculating the tidal dissipation timescale. We find that systems with short tidal dissipation timescales are preferentially aligned and systems with long tidal dissipation timescales have a broad range of obliquities.

arXiv comment12 pages, 4 Figures, Accepted for publication in MNRAS

References in corpus (37)

• Hot Stars with Hot Jupiters Have High Obliquities
• Obliquities of Hot Jupiter host stars: Evidence for tidal interactions and primordial misalignments
• Spin-orbit angle measurements for six southern transiting planets; New insights into the dynamical origins of hot Jupiters
• Chaotic star formation and the alignment of stellar rotation with disc and planetary orbital axes
• The Rossiter-McLaughlin effect and analytic radial velocity curves for transiting extrasolar planetary systems
• Prospects for the Characterization and Confirmation of Transiting Exoplanets via the Rossiter-McLaughlin Effect
• WASP-1b and WASP-2b: Two new transiting exoplanets detected with SuperWASP and SOPHIE
• Starspots, spin-orbit misalignment, and active latitudes in the HAT-P-11 exoplanetary system
• HAT-P-7: A Retrograde or Polar Orbit, and a Third Body
• Evolution of Spin Direction of Accreting Magnetic Protostars and Spin-Orbit Misalignment in Exoplanetary Systems
• The hot-Jupiter Kepler-17b: discovery, obliquity from stroboscopic starspots, and atmospheric characterization
• Rotation Periods, Variability Properties and Ages for Kepler Exoplanet Candidate Host Stars
• Low stellar obliquities in compact multiplanet systems
• WASP-8b: a retrograde transiting planet in a multiple system
• Kepler-63b: A Giant Planet in a Polar Orbit around a Young Sun-like Star
• The retrograde orbit of the HAT-P-6b exoplanet
• Planet-Planet Eclipse and the Rossiter-McLaughlin Effect of a Multiple Transiting System: Joint Analysis of the Subaru Spectroscopy and the Kepler Photometry
• On the orbit of the short-period exoplanet WASP-19b
• Measurement of the Spin-Orbit Misalignment of KOI-13.01 from its Gravity-Darkened Kepler Transit Lightcurve
• WASP-80b: a gas giant transiting a cool dwarf
• On the alignment of debris disks and their host stars' rotation axis -implications for spin-orbit misalignment in exoplanetary systems
• Measurement of Spin-Orbit Misalignment and Nodal Precession for the Planet around Pre-Main-Sequence Star PTFO 8-8695 From Gravity Darkening
• Spin-orbit inclinations of the exoplanetary systems HAT-P-8, HAT-P-9, HAT-P-16 and HAT-P-23
• Spin-Orbit Alignment for the Circumbinary Planet Host Kepler-16A
• The spin-orbit angles of the transiting exoplanets WASP-1b, WASP-24b, WASP-38b and HAT-P-8b from Rossiter-McLaughlin observations
• Alignment in star-debris disc systems seen by Herschel
• The Time Dependence of hot Jupiters' Orbital Inclinations
• Rotation periods of exoplanet host stars
• Analysis of spin-orbit alignment in the WASP-32, WASP-38, and HAT-P-27/WASP-40 systems
• A highly inclined orbit for the 110-day period M-dwarf companion KOI-368.01
• The Homogeneous Study of Transiting Systems (HoSTS) I. The Pilot Study of WASP-13
• The 0.5M${}_J$ transiting exoplanet WASP-13b
• Confirmation of a Retrograde Orbit for Exoplanet WASP-17b
• Estimating the masses of extra-solar planets
• Star - Planet - Debris Disk Alignment in the HD 82943 system: Is planetary system coplanarity actually the norm?
• WASP-32b: A transiting hot Jupiter planet orbiting a lithium-poor, solar-type star
• Transiting exoplanets from the CoRoT space mission. XVIII. CoRoT-18b: a massive hot jupiter on a prograde, nearly aligned orbit

Cited by in corpus (14)

• Stellar obliquities in exoplanetary systems
• The Rossiter-McLaughlin effect reloaded: Probing the 3D spin-orbit geometry, differential stellar rotation, and the spatially-resolved stellar spectrum of star-planet systems
• Orbital misalignment of the Neptune-mass exoplanet GJ 436b with the spin of its cool star
• A Preponderance of Perpendicular Planets
• SOPHIE velocimetry of Kepler transit candidates XII. KOI-1257 b: a highly eccentric three-month period transiting exoplanet
• The GAPS Programme with HARPS-N at TNG VIII: Observations of the Rossiter-McLaughlin effect and characterisation of the transiting planetary systems HAT-P-36 and WASP-11/HAT-P-10
• Spi-OPS: Spitzer and CHEOPS confirm the near-polar orbit of MASCARA-1 b and reveal a hint of dayside reflection
• DREAM II. The spin-orbit angle distribution of close-in exoplanets under the lens of tides
• Spin-orbit alignments for Three Transiting Hot Jupiters: WASP-103b, WASP-87b, & WASP-66b
• Keplerian periodogram for Doppler exoplanets detection: optimized computation and analytic significance thresholds
• Featureless transmission spectra of 12 giant exoplanets observed by GTC/OSIRIS
• Activity time series of old stars from late F to early K. V. Effect on exoplanet detectability with high-precision astrometry
• The study on transiting systems HAT-P-13, HAT-P-16 and WASP-32 through combining ground-based and TESS photometry
• Evidence for the Late Arrival of Hot Jupiters in Systems with High Host-star Obliquities