The smallest planetary drivers of white dwarf pollution

Abstract

Many potential mechanisms for delivering planetary debris to within a few Roche radii of white dwarfs rely on gravitational scattering events that feature perturbers which are giant planets or terrestrial planets. However, the population of these planets orbiting white dwarfs is still unknown, and for a substantial fraction of white dwarfs the largest planetary survivors of stellar evolution may be sub-terrestrial mass minor planets. Here, we attempt to identify the smallest mass perturbers that could pollute white dwarfs. Through computationally expensive numerical simulations of both unstable and stable configurations of minor planets, we find that this critical lower bound equals approximately one Luna mass. Further, we find that as this mass limit is approached from above, the typical cooling age at which white dwarf pollution occurs increases. Consequently, there is a two order-of-magnitude range of perturber masses between Earth and its moon that has remained largely unexplored in white dwarf pollution studies, despite the potential formation of thousands of such Luna-sized objects in these systems.

Accepted for publication in MNRAS

References in corpus (37)

• One or more bound planets per Milky Way star from microlensing observations
• The frequency of planetary debris around young white dwarfs
• The Chemical Composition of an Extrasolar Minor Planet
• Foretellings of Ragnarök: World-engulfing Asymptotic Giants and the Inheritance of White Dwarfs
• Formation of planetary debris discs around white dwarfs I: Tidal disruption of an extremely eccentric asteroid
• A Giant Planet Candidate Transiting a White Dwarf
• A planetesimal orbiting within the debris disc around a white dwarf star
• Accretion of a giant planet onto a white dwarf
• Oxygen fugacities of extrasolar rocks: Evidence for an Earth-like geochemistry of exoplanets
• The Chemical Composition of an Extrasolar Kuiper-Belt-Object
• $Gaia$ white dwarfs within 40 pc II: the volume-limited northern hemisphere sample
• Likely detection of water-rich asteroid debris in a metal-polluted white dwarf
• Detectable close-in planets around white dwarfs through late unpacking
• A Jovian analogue orbiting a white dwarf star
• Tidal disruption of planetary bodies by white dwarfs I: A hybrid SPH-analytical approach
• The orbital evolution of asteroids, pebbles and planets from giant branch stellar radiation and winds
• The Effect of Tides on the Population of PN from Interacting Binaries
• A white dwarf accreting planetary material determined from X-ray observations
• The Fate of Exomoons in White Dwarf Planetary Systems
• Solar Abundances of Rock Forming Elements, Extreme Oxygen and Hydrogen in a Young Polluted White Dwarf
• White dwarf pollution by hydrated planetary remnants: Hydrogen and Metals in WD J204713.76-125908.9
• Revisiting the Long-Period Transiting Planets from Kepler
• The fates of Solar system analogues with one additional distant planet
• Speeding past planets? Asteroids radiatively propelled by giant branch Yarkovsky effects
• Do instabilities in high-multiplicity systems explain the existence of close-in white dwarf planets?
• Post-main-sequence debris from rotation-induced YORP break-up of small bodies II: multiple fissions, internal strengths and binary production
• How Jupiters save or destroy inner Neptunes around evolved stars
• Icy Exomoons Evidenced by Spallogenic Nuclides in Polluted White Dwarfs
• Understanding the origin of white dwarf atmospheric pollution by dynamical simulations based on detected three-planet systems
• Accretion of tidally disrupted asteroids onto white dwarfs: direct accretion versus disk processing
• GD424 -- a helium-atmosphere white dwarf with a large amount of trace hydrogen in the process of digesting a rocky planetesimal
• Successive common envelope events from multiple planets
• Dynamical evolution of two-planet systems and its connection with white dwarf atmospheric pollution
• The entry geometry and velocity of planetary debris into the Roche sphere of a white dwarf
• Rapid Formation of Exoplanetesimals Revealed by White Dwarfs
• White dwarf planetary debris dependence on physical structure distributions within asteroid belts
• The grain size survival threshold in one-planet post-main-sequence exoplanetary systems