Liberating exomoons in white dwarf planetary systems

Abstract

Previous studies indicate that more than a quarter of all white dwarf (WD) atmospheres are polluted by remnant planetary material, with some WDs being observed to accrete the mass of Pluto in 10^6 years. The short sinking timescale for the pollutants indicate that the material must be frequently replenished. Moons may contribute decisively to this pollution process if they are liberated from their parent planets during the post-main-sequence evolution of the planetary systems. Here, we demonstrate that gravitational scattering events among planets in WD systems easily triggers moon ejection. Repeated close encounters within tenths of a planetary Hill radii are highly destructive to even the most massive, close-in moons. Consequently, scattering increases both the frequency of perturbing agents in WD systems, as well as the available mass of polluting material in those systems, thereby enhancing opportunities for collision and fragmentation and providing more dynamical pathways for smaller bodies to reach the WD. Moreover, during intense scattering, planets themselves have pericenters with respect to the WD of only a fraction of an AU, causing extreme Hill-sphere contraction, and the liberation of moons into WD-grazing orbits. Many of our results are directly applicable to exomoons orbiting planets around main sequence stars.

Published (MNRAS): First published online January 19, 2016

References in corpus (72)

• Comprehensive analytic formulae for stellar evolution as a function of mass and metallicity
• A Tidally-Disrupted Asteroid Around the White Dwarf G29-38
• One or more bound planets per Milky Way star from microlensing observations
• A disintegrating minor planet transiting a white dwarf
• Are There Unstable Planetary Systems Around White Dwarfs?
• The frequency of planetary debris around young white dwarfs
• A gaseous metal disk around a white dwarf
• Ancient planetary systems are orbiting a large fraction of white dwarf stars
• Infrared Signatures of Disrupted Minor Planets at White Dwarfs
• The Initial-Final Mass Relation: Direct Constraints at the Low Mass End
• The Link Between Planetary Systems, Dusty White Dwarfs, and Metal Polluted White Dwarfs
• Foretellings of Ragnarök: World-engulfing Asymptotic Giants and the Inheritance of White Dwarfs
• The initial-final mass relationship of white dwarfs revisited: effect on the luminosity function and mass distribution
• Hot Jupiters and Cool Stars
• Dynamical effects of stellar mass loss on a Kuiper-like belt
• The Great Escape: How Exoplanets and Smaller Bodies Desert Dying Stars
• Formation of planetary debris discs around white dwarfs I: Tidal disruption of an extremely eccentric asteroid
• Discovery of a Candidate for the Coolest Known Brown Dwarf
• Simulations of two-planet systems through all phases of stellar evolution: implications for the instability boundary and white dwarf pollution
• A Sub-Earth-Mass Moon Orbiting a Gas Giant Primary or a High Velocity Planetary System in the Galactic Bulge
• Eccentric Planets and Stellar Evolution as a Cause of Polluted White Dwarfs
• Elemental Compositions of Two Extrasolar Rocky Planetesimals
• On the Orbits of Low-mass Companions to White Dwarfs and the Fates of the Known Exoplanets
• Constraints on the Lifetimes of Disks Resulting from Tidally Destroyed Rocky Planetary Bodies
• Carbon Deficiency in Externally-Polluted White Dwarfs: Evidence for Accretion of Asteroids
• The frequency and infrared brightness of circumstellar discs at white dwarfs
• Planet Engulfment by ~1.5-3 Solar-Mass Red Giants
• Long-term evolution of three-planet systems to the post-Main Sequence and beyond
• Detailed compositional analysis of the heavily polluted DBZ white dwarf SDSS J073842.56+183509.06: A window on planet formation?
• Debris from giant impacts between planetary embryos at large orbital radii
• Stochastic accretion of planetesimals onto white dwarfs: constraints on the mass distribution of accreted material from atmospheric pollution
• Doppler-imaging of the planetary debris disc at the white dwarf SDSS J122859.93+104032.9
• Detectable close-in planets around white dwarfs through late unpacking
• A Trio of Metal-Rich Dust and Gas Disks Found Orbiting Candidate White Dwarfs with K-Band Excess
• Excitation and Propagation of Eccentricity Disturbances in Planetary Systems
• Signs of a faint disc population at polluted white dwarfs
• Variable Emission from a Gaseous Disc around a Metal-Polluted White Dwarf
• Planetary systems and real planetary nebulae from planet destruction near white dwarfs
• The Hunt for Exomoons with Kepler (HEK): V. A Survey of 41 Planetary Candidates for Exomoons
• Multi-Planet Destabilisation and Escape in Post-Main Sequence Systems
• An Exoplanet's Response to Anisotropic Stellar Mass-Loss During Birth and Death
• Hydrogen delivery onto white dwarfs from remnant exo-Oort cloud comets
• A Dusty Disk Around WD1150-153: Explaining the Metals in White Dwarfs by Accretion from the Interstellar Medium versus Debris Disks
• The Hunt for Exomoons with Kepler (HEK): IV. A Search for Moons around Eight M-Dwarfs
• A wide binary trigger for white dwarf pollution
• First versus second generation planet formation in post common envelope binary (PCEB) planetary systems
• Dusty Disks around White Dwarfs I: Origin of Debris Disks
• Gaseous Material Orbiting the Polluted, Dusty White Dwarf HE1349-2305
• Evolution of Planetary Orbits with Stellar Mass Loss and Tidal Dissipation
• Post-main-sequence debris from rotation-induced YORP break-up of small bodies
• Evidence for an external origin of heavy elements in hot DA white dwarfs
• The orbital evolution of asteroids, pebbles and planets from giant branch stellar radiation and winds
• Evaporation and Accretion of Extrasolar Comets Following White Dwarf Kicks
• The Great Escape III: Placing post-main-sequence evolution of planetary and binary systems in a Galactic context
• The Solar System's Post-Main Sequence Escape Boundary
• Signals of exomoons in averaged light curves of exoplanets
• The Great Escape II: Exoplanet Ejection from Dying Multiple Star Systems
• Second generation planet formation in NN Serpentis?
• The effect of planet-planet scattering on the survival of exomoons
• Multiwavelength Transit Observations of the Candidate Disintegrating Planetesimals Orbiting WD 1145+017
• Planet formation from the ejecta of common envelopes
• Extrasolar Binary Planets I: Formation by tidal capture during planet-planet scattering
• Transient outburst events from tidally disrupted asteroids near white dwarfs
• Stability of Satellites in Closely Packed Planetary Systems
• Sublimation-induced orbital perturbations of extrasolar active asteroids and comets: application to white dwarf systems
• The detectability of habitable exomoons with Kepler
• Evolution of Planetary Systems with Time Dependent Stellar Mass Loss
• Do weak magnetic fields prevent hydrogen from accreting onto metal-line white dwarf stars?
• Extrasolar Binary Planets II: Detectability by Transit Observations
• Disrupting Primordial Planet Signatures: The Close Encounter of Two Single-Planet Exosystems in the Galactic Disc
• Formation of irregular and runaway moons/exomoons through moon-moon scattering
• Death by Dynamics: Planetoid-Induced Explosions on White Dwarfs

Cited by in corpus (58)

• A Giant Planet Candidate Transiting a White Dwarf
• Unstable low-mass planetary systems as drivers of white dwarf pollution
• Full-lifetime simulations of multiple unequal-mass planets across all phases of stellar evolution
• Numerical Simulations of Collisional Cascades at the Roche Limits of White Dwarf Stars
• Explaining the variability of WD 1145+017 with simulations of asteroid tidal disruption
• Tidal disruption of planetary bodies by white dwarfs I: A hybrid SPH-analytical approach
• Trace hydrogen in helium atmosphere white dwarfs as a possible signature of water accretion
• White Dwarf Pollution by Asteroids from Secular Resonances
• Does a Differentiated, Carbonate-Rich, Rocky Object Pollute the White Dwarf SDSSJ104341.53+085558.2?
• Tidal disruption of planetary bodies by white dwarfs II: Debris disc structure and ejected interstellar asteroids
• Deposition of steeply infalling debris around white dwarf stars
• The Fate of Exomoons in White Dwarf Planetary Systems
• Planetary Systems Around White Dwarfs
• Numerical Simulations of Gaseous Disks Generated from Collisional Cascades at the Roche Limits of White Dwarf Stars
• Exoplanet recycling in massive white-dwarf debris discs
• Post main sequence evolution of icy minor planets: Implications for water retention and white dwarf pollution
• Circularization of tidal debris around white dwarfs: implications for gas production and dust variability
• The fates of Solar system analogues with one additional distant planet
• Mass and eccentricity constraints on the planetary debris orbiting the white dwarf WD 1145+017
• Linking long-term planetary $N$-body simulations with periodic orbits: application to white dwarf pollution
• The lifetimes of planetary debris discs around white dwarfs
• Post-main-sequence debris from rotation-induced YORP break-up of small bodies II: multiple fissions, internal strengths and binary production
• Tidal circularization of gaseous planets orbiting white dwarfs
• Icy Exomoons Evidenced by Spallogenic Nuclides in Polluted White Dwarfs
• Binary star influence on post-main-sequence multi-planet stability
• Orbital relaxation and excitation of planets tidally interacting with white dwarfs
• Post main sequence evolution of icy minor planets II: water retention and white dwarf pollution around massive progenitor stars
• Effects of non-Kozai mutual inclinations on two-planet system stability through all phases of stellar evolution
• The dynamical history of the evaporating or disrupted ice giant planet around white dwarf WD J0914+1914
• Circumbinary exoplanets and brown dwarfs with the Laser Interferometer Space Antenna
• Post-main-sequence evolution of icy minor planets. III. water retention in dwarf planets and exo-moons and implications for white dwarf pollution
• Exomoons as sources of white dwarf pollution
• Secular chaos in white-dwarf planetary systems: origins of metal pollution and short-period planetary companions
• Dynamical mass and multiplicity constraints on co-orbital bodies around stars
• Chaotic rotation and evolution of asteroids and small planets in high-eccentricity orbits around white dwarfs
• Survivability of radio-loud planetary cores orbiting white dwarfs
• Near-infrared variability in dusty white dwarfs: tracing the accretion of planetary material
• On the role of resonances in polluting white dwarfs by asteroids
• The critical binary star separation for a planetary system origin of white dwarf pollution
• Rapid Formation of Exoplanetesimals Revealed by White Dwarfs
• Constraining planet formation around 6$M_{\odot }$-8$M_{\odot }$ stars
• The smallest planetary drivers of white dwarf pollution
• The white dwarf planet WD J0914+1914 b: barricading potential rocky pollutants?
• Transiting Disintegrating Planetary Debris around WD 1145+017
• A power law decay evolution scenario for polluted single white dwarfs
• The unstable fate of the planet orbiting the A-star in the HD 131399 triple stellar system
• Generating metal-polluting debris in white dwarf planetary systems from small-impact crater ejecta
• Asteroid belt survival through stellar evolution: dependence on the stellar mass
• Eclipse, transit and occultation geometry of planetary systems at exo-syzygy
• High-resolution resonant portraits of a single-planet white dwarf system
• Planetary magnetosphere evolution around post-main-sequence stars
• Planetesimals drifting through dusty and gaseous white dwarf debris discs: Types I, II and III-like migration
• Origin of Ca II emission around polluted white dwarfs
• Constellations of co-orbital planets: horseshoe dynamics, long-term stability, transit timing variations, and potential as SETI beacons
• Binary asteroid dissociation and accretion around white dwarfs
• The formation of transiting circumplanetary debris discs from the disruption of satellite systems during planet-planet scattering
• Three-body Mean Motion Resonance Chains as a Delivery Mechanism for White Dwarf Pollution
• Planets or asteroids? A geochemical method to constrain the masses of White Dwarf pollutants