Enrichment of the HR 8799 planets by minor bodies and dust
arXiv:2005.13562 · doi:10.1051/0004-6361/201936783
Abstract
In the Solar System, minor bodies and dust deliver various materials to planetary surfaces. Several exoplanetary systems are known to host inner and outer belts, analogues of the main asteroid belt and the Kuiper belt. We study the possibility that exominor bodies and exodust deliver volatiles and refractories to the exoplanets in the system HR8799 by performing N-body simulations. The model consists of the host star, four giant planets (HR8799 e, d, c, and b), 650000 test particles representing the inner belt, and 1450000 test particles representing the outer belt. Moreover we modelled dust populations that originate from both belts. Within a million years, the two belts evolve towards the expected dynamical structure (also derived in other works), where mean-motion resonances with the planets carve the analogues of Kirkwood gaps. We find that, after this point, the planets suffer impacts by objects from the inner and outer belt at rates that are essentially constant with time, while dust populations do not contribute significantly to the delivery process. We convert the impact rates to volatile and refractory delivery rates using our best estimates of the total mass contained in the belts and their volatile and refractory content. Over their lifetime, the four giant planets receive between and $10^{-3}M_\bigoplus$ of material from both belts. The total amount of delivered volatiles and refractories, ${5\times10^{-3}\textrm{M}_\bigoplus}$, is small compared to the total mass of the planets, $11\times10^{3}\textrm{M}_\bigoplus$. However, if the planets were formed to be volatile-rich, their exogenous enrichment in refractory material may well be significant and observable, for example with JWST-MIRI. If terrestrial planets exist within the snow line of the system, volatile delivery would be an important astrobiological mechanism and may be observable as atmospheric trace gases.
arXiv comment11 pages, 8 figures, accepted for publication in Astronomy&Astrophysics
References in corpus (40)
- Direct Imaging of Multiple Planets Orbiting the Star HR 8799
- REBOUND: An open-source multi-purpose N-body code for collisional dynamics
- Images of a fourth planet orbiting HR 8799
- A giant planet imaged in the disk of the young star Beta Pictoris
- The Occurrence and Architecture of Exoplanetary Systems
- Probabilistic Forecasting of the Masses and Radii of Other Worlds
- Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Northern Sample I
- The Mid-Infrared Instrument for the James Webb Space Telescope I: Introduction
- The taxonomic distribution of asteroids from multi-filter all-sky photometric surveys
- How Observations of Circumstellar Disk Asymmetries Can Reveal Hidden Planets: Pericenter Glow and its Application to the HR 4796 Disk
- The Tucana/Horologium, Columba, AB Doradus, and Argus Associations: New Members and Dusty Debris Disks
- The Debris Disk Around HR 8799
- The Insignificance of P-R Drag in Detectable Extrasolar Planetesimal Belts
- Asteroid Belts in Debris Disk Twins: VEGA and FOMALHAUT
- Dynamical Model for the Zodiacal Cloud and Sporadic Meteors
- The Compositions of Kuiper Belt Objects
- Hybrid Symplectic Integrators for Planetary Dynamics
- Dynamical Constraints on the HR 8799 Planets with GPI
- A Primordial Origin of the Laplace Relation Among the Galilean Satellites
- Herschel images of Fomalhaut. An extrasolar Kuiper Belt at the height of its dynamical activity
- Volatile Delivery to Planets from Water-rich Planetesimals around Low Mass Stars
- Resolved Imaging of the HR 8799 Debris Disk with Herschel
- The CHARA Array Angular Diameter of HR 8799 Favors Planetary Masses for Its Imaged Companions
- Resolving the Planetesimal Belt of HR 8799 with ALMA
- Multiple mean motion resonances in the HR 8799 planetary system
- The HOSTS survey - Exozodiacal dust measurements for 30 stars
- A resolved debris disk around the candidate planet-hosting star HD95086
- An Exo-Kuiper Belt and An Extended Halo around HD 191089 in Scattered Light
- The Scattered Disc of HR 8799
- Delivery of organics to Mars through asteroid and comet impacts
- Planetary and satellite three body mean motion resonances
- The orbital architecture and debris disks of the HR 8799 planetary system
- Long-term stability of the HR 8799 planetary system without resonant lock
- Asteroid impacts on terrestrial planets: The effects of super-Earths and the role of the resonance
- Shaping HR8799's outer dust belt with an unseen planet
- Exocomets in the Proxima Centauri system and their importance for water transport
- Modelling the Inner Debris Disc of HR 8799
- The dynamical structure of HR 8799's inner debris disk
- Prospects for the characterisation of exo-zodiacal dust with the VLTI
- Late Delivery of Nitrogen to Earth