On the Degree of Dynamical Packing in the Kepler Multi-planet Systems
arXiv:2306.12967 · doi:10.1093/mnras/stad1921
Abstract
Current planet formation theories rely on initially compact orbital configurations undergoing a (possibly extended) phase of giant impacts following the dispersal of the dissipative protoplanetary disk. The orbital architectures of observed mature exoplanet systems have likely been strongly sculpted by chaotic dynamics, instabilities, and giant impacts. One possible signature of systems continually reshaped by instabilities and mergers is their dynamical packing. Early Kepler data showed that many multi-planet systems are maximally packed - placing an additional planet between an observed pair would make the system unstable. However, this result relied on placing the inserted planet in the most optimistic configuration for stability (e.g., circular orbits). While this would be appropriate in an ordered and dissipative picture of planet formation (i.e. planets dampen into their most stable configurations), we argue that this best-case scenario for stability is rarely realized due to the strongly chaotic nature of planet formation. Consequently, the degree of dynamical packing in multi-planet systems under a realistic formation model is likely significantly higher than previously realized. We examine the full Kepler multi planet sample through this new lens, showing that ~60-95% of Kepler multi-planet systems are strongly packed and that dynamical packing increases with multiplicity. This may be a signature of dynamical sculpting or of undetected planets, showing that dynamical packing is an important metric that can be incorporated into planet formation modelling or when searching for unseen planets.
arXiv comment15 pages, 4 figures. Accepted for publication in MNRAS
References in corpus (66)
- Array Programming with NumPy
- Astropy: A Community Python Package for Astronomy
- Gaia Data Release 2. Summary of the contents and survey properties
- The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
- The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
- Seven temperate terrestrial planets around the nearby ultracool dwarf star TRAPPIST-1
- REBOUND: An open-source multi-purpose N-body code for collisional dynamics
- Planetary Candidates Observed by Kepler, III: Analysis of the First 16 Months of Data
- Architecture and Dynamics of Kepler's Candidate Multiple Transiting Planet Systems
- 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
- WHFast: A fast and unbiased implementation of a symplectic Wisdom-Holman integrator for long term gravitational simulations
- Planetary Candidates Observed by Kepler. VIII. A Fully Automated Catalog With Measured Completeness and Reliability Based on Data Release 25
- Observations of Protoplanetary Disk Structures
- Breaking the Chains: Hot Super-Earth systems from migration and disruption of compact resonant chains
- A seven-planet resonant chain in TRAPPIST-1
- Identifying Exoplanets with Deep Learning: A Five Planet Resonant Chain around Kepler-80 and an Eighth Planet around Kepler-90
- The California-Kepler Survey V. Peas in a Pod: Planets in a Kepler Multi-planet System are Similar in Size and Regularly Spaced
- Planet Formation by Coagulation: A Focus on Uranus and Neptune
- Eccentricity from transit photometry: small planets in Kepler multi-planet systems have low eccentricities
- About 30% of Sun-like Stars Have Kepler-like Planetary Systems: A Study of their Intrinsic Architecture
- Testing In Situ Assembly with the Kepler Planet Candidate Sample
- The orbital eccentricity of small planet systems
- Exoplanet Orbital Eccentricities Derived From LAMOST-Kepler Analysis
- Architecture of Planetary Systems Based on Kepler Data: Number of Planets and Coplanarity
- A resonant chain of four transiting, sub-Neptune planets
- Kepler Planet Masses and Eccentricities from TTV Analysis
- Overstable Librations can account for the Paucity of Mean Motion Resonances among Exoplanet Pairs
- First order resonance overlap and the stability of close two planet systems
- An Excess of Jupiter Analogs in Super-Earth Systems
- The Super Earth-Cold Jupiter Relations
- The Gaia-Kepler Stellar Properties Catalog. II. Planet Radius Demographics as a Function of Stellar Mass and Age
- Kepler Multi-Planet Systems Exhibit Unexpected Intra-system Uniformity in Mass and Radius
- Are Planetary Systems Filled to Capacity? A Study Based on Kepler Results
- The (In)Stability of Planetary Systems
- Predicting the long-term stability of compact multiplanet systems
- Convergent Migration Renders TRAPPIST-1 Long-lived
- Predicting Planets in Known Extra-Solar Planetary Systems I: Test Particle Simulations
- The stability of tightly-packed, evenly-spaced systems of Earth-mass planets orbiting a Sun-like star
- Architectures of Exoplanetary Systems. III: Eccentricity and Mutual Inclination Distributions of AMD-stable Planetary Systems
- Correlations between compositions and orbits established by the giant impact era of planet formation
- Accounting for Incompleteness due to Transit Multiplicity in Kepler Planet Occurrence Rates
- A 1.9 Earth radius rocky planet and the discovery of a non-transiting planet in the Kepler-20 system
- The statistical mechanics of planet orbits
- A Criterion for the Onset of Chaos in Systems of Two Eccentric Planets
- Planet Hunters. VIII. Characterization of 41 Long-Period Exoplanet Candidates from Kepler Archival Data
- CKS VIII: Eccentricities of Kepler Planets and Tentative Evidence of a High Metallicity Preference for Small Eccentric Planets
- Planet Hunters. VI: An Independent Characterization of KOI-351 and Several Long Period Planet Candidates from the Kepler Archival Data
- Exoplanet Imitators: A test of stellar activity behavior in radial velocity signals
- The multiplicity distribution of Kepler's exoplanets
- The onset of instability in resonant chains
- Revisiting the Long-Period Transiting Planets from Kepler
- Insights into planet formation from debris disks: II. Giant impacts in extrasolar planetary systems
- Breaking Resonant Chains: Destabilization of Resonant Planets due to Long-term Mass Evolution
- Forming Diverse Super-Earth Systems in Situ
- Formation of compact systems of super-Earths via dynamical instabilities and giant impacts
- A Criterion for the Stability of Planets in Chains of Resonances
- Fundamental limits from chaos on instability time predictions in compact planetary systems
- The "Breaking The Chains" migration model for super-Earths formation: the effect of collisional fragmentation
- Edge-of-the-Multis: Evidence for a Transition in the Outer Architectures of Compact Multi-Planet Systems
- Formation of Close-in Super-Earths by Giant Impacts: Effects of Initial Eccentricities and Inclinations of Protoplanets
- Pairwise Tidal Equilibrium States and the Architecture of Extrasolar Planetary Systems
- Formation of Terrestrial Planets
- How Close are Compact Multi-Planet Systems to the Stability Limit?
- Stability Constrained Characterization of Multiplanet Systems
- Energy Optimization in Binary Star Systems: Explanation for Equal Mass Members in Close Orbits