A Tidal Origin for a 3-body Resonance in Kepler-221

Abstract

Over the course of the last two decades, traditional models of planet formation have been repeatedly challenged by the emerging census of extrasolar planets. Key among them is the orbital architecture problem: while standard models of orbital migration predict resonant orbits for short-period objects, most planets do not appear to lie in orbital resonances. Here we show that the four-planet system Kepler-221, not previously recognized to have active orbital resonances, has a three-body commensurability relation unique within the Kepler sample. Using a suite of numerical experiments as well as a perturbative analysis, we demonstrate that this system likely began as a resonant chain and proceeded to undergo large-scale divergence away from resonance, under the action of tidal dissipation. Our results further indicate that obliquity tides, driven by a secular spin-orbit resonance and mutual inclination, are an excellent candidate for driving this orbital divergence, and that the high tidal luminosity may also explain the anomalous size of planet b, which lies within the Fulton radius gap.

arXiv comment15 pages, 9 figures, accepted for publication in AJ

References in corpus (44)

• Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1
• The California-Kepler Survey. III. A Gap in the Radius Distribution of Small Planets
• Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics
• Architecture of Kepler's Multi-transiting Systems: II. New investigations with twice as many candidates
• Probabilistic Forecasting of the Masses and Radii of Other Worlds
• Chromospheric Activity and Jitter Measurements for 2630 Stars on the California Planet Search
• WHFast: A fast and unbiased implementation of a symplectic Wisdom-Holman integrator for long term gravitational simulations
• A torque formula for non-isothermal Type I planetary migration - I. Unsaturated horseshoe drag
• Breaking the Chains: Hot Super-Earth systems from migration and disruption of compact resonant chains
• The California-Kepler Survey V. Peas in a Pod: Planets in a Kepler Multi-planet System are Similar in Size and Regularly Spaced
• The California-Kepler Survey. I. High Resolution Spectroscopy of 1305 Stars Hosting Kepler Transiting Planets
• The Lick-Carnegie Exoplanet Survey: A Uranus-mass Fourth Planet for GJ 876 in an Extrasolar Laplace Configuration
• Densities and Eccentricities of 139 Kepler Planets from Transit Time Variations
• REBOUNDx: A Library for Adding Conservative and Dissipative Forces to Otherwise Symplectic N-body Integrations
• Dissipative Divergence of Resonant Orbits
• A resonant chain of four transiting, sub-Neptune planets
• 197 Candidates and 104 Validated Planets in K2's First Five Fields
• Resonant Repulsion of Kepler Planet Pairs
• Six transiting planets and a chain of Laplace resonances in TOI-178
• The Physics of Bodily Tides in Terrestrial Planets, and the Appropriate Scales of Dynamical Evolution
• Kepler Multi-Planet Systems Exhibit Unexpected Intra-system Uniformity in Mass and Radius
• Forward and Inverse Modeling of the Emission and Transmission Spectrum of GJ 436b: Investigating Metal Enrichment, Tidal Heating, and Clouds
• Three Body Resonance Overlap in Closely Spaced Multiple Planet Systems
• A Dynamical Analysis of the Kepler-80 System of Five Transiting Planets
• Predicting the long-term stability of compact multiplanet systems
• Obliquity-Driven Sculpting of Exoplanetary Systems
• Tidally-Induced Radius Inflation of Sub-Neptunes
• Are the Kepler Near-Resonance Planet Pairs due to Tidal Dissipation?
• The Laplace resonance in the Kepler-60 system
• The K2-138 System: A Near-Resonant Chain of Five Sub-Neptune Planets Discovered by Citizen Scientists
• Dissipation in planar resonant planetary systems
• On the dynamics of multiple systems of hot super-Earths and Neptunes: Tidal circularization, resonance and the HD 40307 system
• Analytical model of multi-planetary resonant chains and constraints on migration scenarios
• A dynamical analysis of the Kepler-11 planetary system
• Dynamics and Formation of the Near-Resonant K2-24 System: Insights from Transit-Timing Variations and Radial Velocities
• Review: A Coherent and Comprehensive Model of the Evolution of the Outer Solar System
• Tides Alone Cannot Explain Kepler Planets Close to 2:1 MMR
• Resonance Capture and Dynamics of 3-Planet Systems
• Identifying Young $Kepler$ Planet Host Stars from Keck-HIRES Spectra of Lithium
• Planetary and satellite three body mean motion resonances
• The role of dissipative evolution for three-planet, near-resonant extrasolar systems
• K2-19b and c are in a 3:2 Commensurability but out of Resonance: A Challenge to Planet Assembly by Convergent Migration
• Chaotic Excitation and Tidal Damping in the GJ 876 System
• The origins of nearly coplanar, non-resonant systems of close-in super-Earths

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• The Origin of Universality in the Inner Edges of Planetary Systems
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• Is the orbital distribution of multiplanet systems influenced by pure three-planet resonances?
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• Kepler-80 Revisited: Assessing the Participation of a Newly Discovered Planet in the Resonant Chain
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• Tidally Heated Sub-Neptunes, Refined Planetary Compositions, and Confirmation of a Third Planet in the TOI-1266 System
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