A Preponderance of Perpendicular Planets

Abstract

Observing the Rossiter-McLaughlin effect during a planetary transit allows the determination of the angle $\lambda$ between the sky projections of the star's spin axis and the planet's orbital axis. Such observations have revealed a large population of well-aligned systems and a smaller population of misaligned systems, with values of $\lambda$ ranging up to 180${}^{\circ }$. For a subset of 57 systems, we can now go beyond the sky projection and determine the 3-d obliquity $\psi$ by combining the Rossiter-McLaughlin data with constraints on the line-of-sight inclination of the spin axis. Here we show that the misaligned systems do not span the full range of obliquities; they show a preference for nearly-perpendicular orbits ($\psi =80-125^{\circ }$) that seems unlikely to be a statistical fluke. If confirmed by further observations, this pile-up of polar orbits is a clue about the unknown processes of obliquity excitation and evolution.

arXiv commentaccepted version, ApJL

References in corpus (97)

• Astropy: A Community Python Package for Astronomy
• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• Shrinking binary and planetary orbits by Kozai cycles with tidal friction
• Obliquities of Hot Jupiter host stars: Evidence for tidal interactions and primordial misalignments
• Homogeneous studies of transiting extrasolar planets. IV. Thirty systems with space-based light curves
• Hot Jupiters from Secular Planet--Planet Interactions
• Spin-orbit angle measurements for six southern transiting planets; New insights into the dynamical origins of hot Jupiters
• The GAPS Programme with HARPS-N@TNG XIV. Investigating giant planet migration history via improved eccentricity and mass determination for 231 transiting planets
• Nightside condensation of iron in an ultra-hot giant exoplanet
• Exoplanetary Spin-Orbit Alignment: Results from the Ensemble of Rossiter-McLaughlin Observations
• Evidence of Possible Spin-Orbit Misalignment Along the Line of Sight in Transiting Exoplanet Systems
• Starspots, spin-orbit misalignment, and active latitudes in the HAT-P-11 exoplanetary system
• Stellar Rotation Periods of the Kepler Objects of Interest: A Dearth of Close-in Planets around Fast Rotators
• Misaligned spin-orbit in the XO-3 planetary system?
• 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
• Tidal Dissipation in Planet-Hosting Stars: Damping of Spin-Orbit Misalignment and Survival of Hot Jupiters
• Starspots and spin-orbit alignment in the WASP-4 exoplanetary system
• The Rossiter-McLaughlin effect reloaded: Probing the 3D spin-orbit geometry, differential stellar rotation, and the spatially-resolved stellar spectrum of star-planet systems
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• Formation and Stellar Spin-Orbit Misalignment of Hot Jupiters from Lidov-Kozai Oscillations in Stellar Binaries
• 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
• Orbital misalignment of the Neptune-mass exoplanet GJ 436b with the spin of its cool star
• Photometric Amplitude Distribution of Stellar Rotation of Kepler KOIs-Indication for Spin-Orbit Alignment of Cool Stars and High Obliquity for Hot Stars
• The GAPS programme with HARPS-N at TNG. I: Observations of the Rossiter-McLaughlin effect and characterisation of the transiting system Qatar-1
• On the Inference of a Star's Inclination Angle from its Rotation Velocity and Projected Rotation Velocity
• Atmospheric Characterization of the Hot Jupiter Kepler-13Ab
• The retrograde orbit of the HAT-P-6b exoplanet
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• Transits and starspots in the WASP-19 planetary system
• Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS) III. Atmospheric structure of the misaligned ultra-hot Jupiter WASP-121b
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• The hot dayside and asymmetric transit of WASP-189b seen by CHEOPS
• The Rotation Period of the Planet-Hosting Star HD 189733
• TESS Hunt for Young and Maturing Exoplanets (THYME) III: a two-planet system in the 400 Myr Ursa Major Group
• Mass loss rate and local thermodynamic state of KELT-9 b thermosphere from the hydrogen Balmer series
• Evolution of Spin Direction of Accreting Magnetic Protostars and Spin-Orbit Misalignment in Exoplanetary Systems: II. Warped Discs
• The GAPS Programme with HARPS-N at TNG XVI: Measurement of the Rossiter-McLaughlin effect of the transiting planetary systems HAT-P-3, HAT-P-12, HAT-P-22, WASP-39 and WASP-60
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• Detection of Na, K, and H$\alpha$ absorption in the atmosphere of WASP-52b using ESPRESSO
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• Measurement of the Nodal Precession of WASP-33 b via Doppler Tomography
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• KELT-17b: A hot-Jupiter transiting an A-star in a misaligned orbit detected with Doppler tomography
• The Habitable-zone Planet Finder Reveals A High Mass and a Low Obliquity for the Young Neptune K2-25b
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• The GAPS Programme with HARPS-N at TNG. XIII. The orbital obliquity of three close-in massive planets hosted by dwarf K-type stars: WASP-43, HAT-P-20 and Qatar-2
• Asteroseismic inference on the spin-orbit misalignment and stellar parameters of HAT-P-7
• Qatar-2: A K dwarf orbited by a transiting hot Jupiter and a more massive companion in an outer orbit
• Spin-Orbit Angles of Kepler-13Ab and HAT-P-7b from Gravity-Darkened Transit Light Curves
• Stellar rotation--planetary orbit period commensurability in the HAT-P-11 system
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• 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
• A High Stellar Obliquity in the WASP-7 Exoplanetary System
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• Stellar Spin-Orbit Alignment for Kepler-9, a Multi-transiting Planetary system with Two Outer Planets Near 2:1 Resonance
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• Evidence for Spin-orbit Alignment in the TRAPPIST-1 System
• A well aligned orbit for the 45 Myr old transiting Neptune DS Tuc Ab
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• Refined architecture of the WASP-8 system: a cautionary tale for traditional Rossiter-McLaughlin analysis
• Orbital misalignment of the super-Earth $\pi$ Men c with the spin of its star
• The stellar obliquity, planet mass, and very low albedo of Qatar-2 from K2 Photometry
• Hot Stars With Kepler Planets Have High Obliquities
• K2-290: a warm Jupiter and a mini-Neptune in a triple-star system
• WASP-166b: a bloated super-Neptune transiting a V = 9 star
• TKS III: A Stellar Obliquity Measurement of TOI-1726 c
• Spin-Orbit Misalignments of Three Jovian Planets via Doppler Tomography
• EPIC211089792 b: an aligned and inflated hot jupiter in a young visual binary
• High-precision multi-band time-series photometry of exoplanets Qatar-1b and TrES-5b
• MASCARA-4 b/bRing-1b - A retrograde hot Jupiter around the bright A3V star HD 85628
• Gravity-Darkening Analysis of Misaligned Hot Jupiter MASCARA-4 b
• Broadband transmission spectroscopy of HD209458b with ESPRESSO: Evidence for Na, TiO, or both
• The well-aligned orbit of WASP-84b: evidence for disc migration
• Transiting exoplanets from the CoRoT space mission. XVIII. CoRoT-18b: a massive hot jupiter on a prograde, nearly aligned orbit
• Recurring sets of recurring starspot occultations on exoplanet-host Qatar-2
• A Window on Exoplanet Dynamical Histories: Rossiter-McLaughlin Observations of WASP-13b and WASP-32b
• WASP-189b: an ultra-hot Jupiter transiting the bright A star HR 5599 in a polar orbit
• On a Possible Solution to the Tidal Realignment Problem for Hot Jupiters
• A much lower density for the transiting extrasolar planet WASP-7
• Imaging radial velocity planets with SPHERE
• Rapid rotators revisited: absolute dimensions of KOI-13
• EPIC 246851721 b: A Tropical Jupiter Transiting a Rapidly Rotating Star in a Well-Aligned Orbit

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