Necroplanetology: Simulating the Tidal Disruption of Differentiated Planetary Material Orbiting WD 1145+017

Abstract

The WD 1145+017 system shows irregular transit features that are consistent with the tidal disruption of differentiated asteroids with bulk densities $<4$ g cm${}^{-3}$ and bulk masses $\lesssim 10^{21}$ kg (Veras et al., 2017; arXiv:1610.06926). We use the open-source N-body code REBOUND (Rein and Liu, 2011; arXiv:1110.4876) to simulate this disruption with different internal structures: varying the core volume fraction, mantle/core density ratio, and the presence/absence of a thin low-density crust. We allow the rubble pile to partially disrupt and capture lightcurves at a specific point during the disruption at cadences comparable to those from ground-based photometry. As a proof-of-concept we show that varying these structural parameters have observationally distinguishable effects on the transit light curve as the asteroid is disrupted and compare the simulation-generated lightcurves to data from Gary et al., 2017 (arXiv:1608.00026). With the caveat that our simulations do not model the sublimation in detail or account for its effects on orbital evolution, we find that a low core fraction and low mantle/core density ratio asteroid is most consistent with the stable transit feature present for multiple weeks circa April 2016 (referred to as G6121 in Gary et al., 2017 (arXiv:1608.00026) and A1 in Hallakoun et al., 2017 (arXiv:1702.05483). Connecting tidal disruption simulations to photometry suggests characteristics for the interior structure and composition of an exoplanetary body, information that is only possible because we are observing the death of the planetary system in action. All-sky survey missions such as TESS and LSST will be able to detect other systems like WD 1145+017, creating a sample of subjects for a new subfield of planetary science: necroplanetology.

arXiv commentAccepted for publication in the Astrophysical Journal on the 11th of March, 2020. 14 pages, 3 figures, 2 tables. Pre-proofs

References in corpus (53)

• emcee: The MCMC Hammer
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• Planet Occurrence within 0.25 AU of Solar-type Stars from Kepler
• REBOUND: An open-source multi-purpose N-body code for collisional dynamics
• 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
• The frequency of planetary debris around young white dwarfs
• Ancient planetary systems are orbiting a large fraction of white dwarf stars
• The Chemical Composition of an Extrasolar Minor Planet
• Circumstellar Debris and Pollution at White Dwarf Stars
• 55 Cancri (Copernicus): A Multi-Planet System with a Hot Super-Earth and a Jupiter Analogue
• 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
• Accretion of a giant planet onto a white dwarf
• Cool DZ white dwarfs II: Compositions and evolution of old remnant planetary systems
• Oxygen fugacities of extrasolar rocks: Evidence for an Earth-like geochemistry of exoplanets
• Evolution of OH and CO-dark Molecular Gas Fraction Across a Molecular Cloud Boundary In Taurus
• Polluted White Dwarfs: Constraints on the Origin and Geology of Exoplanetary Material
• Drifting Asteroid Fragments Around WD 1145+017
• High-speed photometry of the disintegrating planetesimals at WD1145+017: evidence for rapid dynamical evolution
• Compositional evolution during rocky protoplanet accretion
• A Dusty Disk Around WD1150-153: Explaining the Metals in White Dwarfs by Accretion from the Interstellar Medium versus Debris Disks
• Rocky Planetesimals as the Origin of Metals in DZ Stars
• Explaining the variability of WD 1145+017 with simulations of asteroid tidal disruption
• Does a Differentiated, Carbonate-Rich, Rocky Object Pollute the White Dwarf SDSSJ104341.53+085558.2?
• Are exoplanetesimals differentiated?
• Multiwavelength Transit Observations of the Candidate Disintegrating Planetesimals Orbiting WD 1145+017
• Planet formation from the ejecta of common envelopes
• Spectroscopic Evolution of Disintegrating Planetesimals: Minutes to Months Variability in the Circumstellar Gas Associated with WD 1145+017
• WD 1145+017 Photometric Observations During 8 Months of High Activity
• The First Post-Kepler Brightness Dips of KIC 8462852
• Solar Abundances of Rock Forming Elements, Extreme Oxygen and Hydrogen in a Young Polluted White Dwarf
• Gray transits of WD 1145+017 over the visible band
• Evidence for eccentric, precessing gaseous debris in the circumstellar absorption towards WD 1145+017
• Exoplanet recycling in massive white-dwarf debris discs
• Sublimation-induced orbital perturbations of extrasolar active asteroids and comets: application to white dwarf systems
• A dearth of small particles in the transiting material around the white dwarf WD 1145+017
• Magnetism, X-rays, and Accretion Rates in WD 1145+017 and other Polluted White Dwarf Systems
• Modeling of the Variable Circumstellar Absorption Features of WD 1145+017
• Simultaneous infrared and optical observations of the transiting debris cloud around WD 1145+017
• 1I/2017 'Oumuamua-like Interstellar Asteroids as Possible Messengers from the Dead Stars
• Mass and eccentricity constraints on the planetary debris orbiting the white dwarf WD 1145+017
• A new paradigm for reproducing and analyzing N-body simulations of planetary systems
• Fast spectrophotometry of WD 1145+017
• Tidal disruption of satellites and formation of narrow rings
• Constraining the origin of the planetary debris surrounding ZTF J0139+5245 through rotational fission of a triaxial asteroid
• Once in a blue moon: detection of 'bluing' during debris transits in the white dwarf WD1145+017
• Shallow Ultraviolet Transits of WD 1145+017
• Dynamical mass and multiplicity constraints on co-orbital bodies around stars
• Magnetospherically-trapped dust and a possible model for the unusual transits at WD 1145+017
• Pole, Pericenter, and Nodes of the Interstellar Minor Body A/2017 U1

Cited by in corpus (10)

• Planetary Systems Around White Dwarfs
• The lifetimes of planetary debris discs around white dwarfs
• Asynchronous accretion can mimic diverse white dwarf pollutants I: core and mantle fragments
• On the role of resonances in polluting white dwarfs by asteroids
• Emission from elliptical streams of dusty debris around white dwarfs
• Can tidal evolution lead to close-in planetary bodies around white dwarfs I: Orbital period distribution
• Can tidal evolution lead to close-in planetary bodies around white dwarfs II: volcanism and transits
• Planetesimals drifting through dusty and gaseous white dwarf debris discs: Types I, II and III-like migration
• Partial disruption of a planet around a white dwarf: the effect of perturbation from the remnant planet on the accretion
• Disruption of exo-asteroids around white dwarfs and the release of dust particles in debris rings in co-orbital motion