TOI-1259Ab: A Warm Jupiter Orbiting a K-dwarf White-Dwarf Binary is on a Well-aligned Orbit

Abstract

The evolution of one member of a stellar binary into a white dwarf has been proposed as a mechanism that triggers the formation of close-in gas giant planets. The star's asymmetric mass loss during the AGB stage gives it a "kick" that can initiate Eccentric Lidov-Kozai oscillations, potentially causing a planet around the secondary star to migrate inwards and perturbing the eccentricity and inclination of its orbit. Here we present a measurement of the stellar obliquity of TOI-1259Ab, a gas giant in a close-in orbit around a K star with a white dwarf companion about 1650 au away. By using the NEID spectrograph to detect the Rossiter-McLaughlin effect during the planetary transit, we find the sky-projected obliquity to be $\lambda =6_{-22}^{+21}{}^{\circ }$. When combined with estimates of the stellar rotation period, radius, and projected rotation velocity, we find the true 3D obliquity to be $\psi =24_{-12}^{+14}{}^{\circ }$ ($\psi <48^{\circ }$ at 95% confidence), revealing that the orbit of TOI-1259Ab is well aligned with the star's equatorial plane. Because the planet's orbit is too wide for tidal realignment to be expected, TOI-1259Ab might have formed quiescently in this well-aligned configuration. Alternatively, as we show with dynamical simulations, Eccentric Lidov-Kozai oscillations triggered by the evolution of the binary companion are expected to lead to a low obliquity with a probability of about $\sim$14%.

11 pages, 6 figures, submitted to A&A

References in corpus (59)

• Gaia Data Release 3: Summary of the content and survey properties
• The Transiting Exoplanet Survey Satellite
• Comprehensive analytic formulae for stellar evolution as a function of mass and metallicity
• Shrinking binary and planetary orbits by Kozai cycles with tidal friction
• Fast and scalable Gaussian process modeling with applications to astronomical time series
• The NASA Exoplanet Archive: Data and Tools for Exoplanet Research
• The Eccentric Kozai-Lidov Effect and Its Applications
• Hot Stars with Hot Jupiters Have High Obliquities
• Planet Migration and Binary Companions: the case of HD 80606b
• Obliquities of Hot Jupiter host stars: Evidence for tidal interactions and primordial misalignments
• Origins of Hot Jupiters
• RadVel: The Radial Velocity Modeling Toolkit
• Spectrum radial velocity analyser (SERVAL). High-precision radial velocities and two alternative spectral indicators
• A million binaries from Gaia eDR3: sample selection and validation of Gaia parallax uncertainties
• Secular Chaos and the Production of Hot Jupiters
• The frequency of planetary debris around young white dwarfs
• Tidal dissipation in rotating solar-type stars
• Ancient planetary systems are orbiting a large fraction of white dwarf stars
• Juliet: a versatile modelling tool for transiting and non-transiting exoplanetary systems
• On the Formation of Hot Jupiters in Stellar Binaries
• Evidence of Possible Spin-Orbit Misalignment Along the Line of Sight in Transiting Exoplanet Systems
• In Situ Formation and Dynamical Evolution of Hot Jupiter Systems
• Multiple-Planet Scattering and the Origin of Hot Jupiters
• Evolution of Spin Direction of Accreting Magnetic Protostars and Spin-Orbit Misalignment in Exoplanetary Systems
• Hot Jupiters from Coplanar High-eccentricity Migration
• A Giant Planet Candidate Transiting a White Dwarf
• Where are the most ancient stars in the Milky Way?
• On the Inference of a Star's Inclination Angle from its Rotation Velocity and Projected Rotation Velocity
• Current challenges in the physics of white dwarf stars
• The In Situ Formation of Giant Planets at Short Orbital Periods
• A Preponderance of Perpendicular Planets
• HAT-P-18b and HAT-P-19b: Two Low-Density Saturn-Mass Planets Transiting Metal-Rich K Stars
• Rossiter--McLaughlin models and their effect on estimates of stellar rotation, illustrated using six WASP systems
• A Versatile Technique to Enable sub-milli-Kelvin Instrument Stability for Precise Radial Velocity Measurements: Tests with the Habitable-zone Planet Finder
• The Warm Neptune GJ 3470b has a Polar Orbit
• Origins of Hot Jupiters from the Stellar Obliquity Distribution
• The Habitable-zone Planet Finder Reveals A High Mass and a Low Obliquity for the Young Neptune K2-25b
• DREAM I. Orbital architecture orrery
• The GAPS Programme with HARPS-N at TNG. III: The retrograde orbit of HAT-P-18b
• A Tendency Toward Alignment in Single-Star Warm Jupiter Systems
• The Occurrence of Wide-Orbit Planets in Binary Star Systems
• Planet Formation in Disks with Inclined Binary Companions: Can Primordial Spin-Orbit Misalignment be Produced?
• The Time Dependence of hot Jupiters' Orbital Inclinations
• The Dynamical Effects of White Dwarf Birth Kicks in Globular Star Clusters
• DREAM II. The spin-orbit angle distribution of close-in exoplanets under the lens of tides
• Obliquities of Exoplanet Host Stars: 19 New and Updated Measurements, and Trends in the Sample of 205 Measurements
• Ponderings on the Possible Preponderance of Perpendicular Planets
• KELT-25b and KELT-26b: A Hot Jupiter and a Substellar Companion Transiting Young A-stars Observed by TESS
• Gaia Search for stellar Companions of TESS Objects of Interest II
• Five transiting hot Jupiters discovered using WASP-South, Euler and TRAPPIST: WASP-119 b, WASP-124 b, WASP-126 b, WASP-129 b and WASP-133 b
• Spin-orbit alignment of the $\beta$ Pictoris planetary system
• WASP-71b: a bloated hot Jupiter in a 2.9-day, prograde orbit around an evolved F8 star
• The Aligned Orbit of the Eccentric Proto Hot Jupiter TOI-3362b
• TOI-1259Ab -- a gas giant planet with 2.7% deep transits and a bound white dwarf companion
• HATS-38 b and WASP-139 b join a growing group of hot Neptunes on polar orbits
• Gaia Search for stellar Companions of TESS Objects of Interest III
• Host-star and exoplanet composition: Polluted white dwarf reveals depletion of moderately refractory elements in planetary material
• Atmospheric Mass Loss from TOI-1259 A b, a Gas Giant Planet With a White Dwarf Companion
• Spectroscopy of TOI-1259B -- an unpolluted white dwarf companion to an inflated warm Saturn