The Aligned Orbit of the Eccentric Proto Hot Jupiter TOI-3362b

Abstract

High-eccentricity tidal migration predicts the existence of highly eccentric proto-hot Jupiters on the "tidal circularization track," meaning that they might eventually become hot Jupiters, but that their migratory journey remains incomplete. Having experienced moderate amounts of the tidal reprocessing of their orbital elements, proto-hot Jupiters systems can be powerful test beds for the underlying mechanisms of eccentricity growth. Notably, they may be used for discriminating between variants of high-eccentricity migration, each predicting a distinct evolution of misalignment between the star and the planet's orbit. We constrain the spin-orbit misalignment of the proto-hot Jupiter TOI-3362b with high-precision radial velocity observations using ESPRESSO at VLT. The observations reveal a sky-projected obliquity $\lambda =1.2_{-2.7}^{+2.8}$ deg and constrain the orbital eccentricity to $e=0.720\pm 0.016$, making it one of the most eccentric gas giants for which the obliquity has been measured. The large eccentricity and the striking orbit alignment of the planet suggest that ongoing coplanar high-eccentricity migration driven by a distant companion is a possible explanation for the system's architecture. This distant companion would need to reside beyond 5 au at 95% confidence to be compatible with the available radial velocity observations.

ApJL 958 L20 (9 pages, 6 figures)

References in corpus (15)

• The Transiting Exoplanet Survey Satellite
• ESPRESSO@VLT -- On-sky performance and first results
• CERES: A Set of Automated Routines for Echelle Spectra
• exoplanet: Gradient-based probabilistic inference for exoplanet data & other astronomical time series
• A Guide to Realistic Uncertainties on Fundamental Properties of Solar-Type Exoplanet Host Stars
• Hot Jupiters from Coplanar High-eccentricity Migration
• Photometric and spectroscopic detection of the primary transit of the 111-day-period planet HD 80606 b
• APASS Landolt-Sloan BVgri photometry of RAVE stars. I. Data, effective temperatures and reddenings
• The Warm Neptune GJ 3470b has a Polar Orbit
• ZASPE: A Code to Measure Stellar Atmospheric Parameters and their Covariance from Spectra
• The Habitable-zone Planet Finder Reveals A High Mass and a Low Obliquity for the Young Neptune K2-25b
• Moderately Eccentric Warm Jupiters from Secular Interactions with Exterior Companions
• Revisiting migration in a disc cavity to explain the high eccentricities of warm Jupiters
• Orbital alignment of the eccentric warm Jupiter TOI-677 b
• Prospects from TESS and Gaia to constrain the flatness of planetary systems

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• A Homogeneous Catalog of Rossiter-McLaughlin Systems: Distinct $e$-$\lambda$ Trends in Three Gas-Giant Mass Regimes
• POSEIDON II: The Anti-Aligned Orbit of the Warm Neptune TOI-1710 A b