
Alexander Mustill
Researcher

Dynamical evolution of two-planet systems and its connection with white dwarf atmospheric pollution
Author
Summary, in English
Asteroid material is detected in white dwarfs (WDs) as atmospheric pollution by metals, in the form of gas/dust discs, or in photometric transits. Within the current paradigm, minor bodies need to be scattered, most likely by planets, into highly eccentric orbits where the material gets disrupted by tidal forces and then accreted on to the star. This can occur through a planet-planet scattering process triggered by the stellar mass-loss during the post main-sequence (MS) evolution of planetary systems. So far, studies of the N-body dynamics of this process have used artificial planetary system architectures built ad hoc. In this work, we attempt to go a step further and study the dynamical instability provided by more restrictive systems that, at the same time, allow us an exploration of a wider parameter space: the hundreds of multiple planetary systems found around MS stars. We find that most of our simulated systems remain stable during the MS, Red, and Asymptotic Giant Branch and for several Gyr into the WD phases of the host star. Overall, only ≈2.3 per\ cent of the simulated systems lose a planet on the WD as a result of dynamical instability. If the instabilities take place during the WD phase most of them result in planet ejections with just five planetary configurations ending as a collision of a planet with the WD. Finally 3.2 per\ cent of the simulated systems experience some form of orbital scattering or orbit crossing that could contribute to the pollution at a sustained rate if planetesimals are present in the same system.
Department/s
- Lund Observatory - Undergoing reorganization
Publishing year
2020
Language
English
Pages
4091-4106
Publication/Series
Monthly Notices of the Royal Astronomical Society
Volume
497
Issue
4
Links
Document type
Journal article
Publisher
Oxford University Press
Topic
- Astronomy, Astrophysics and Cosmology
Keywords
- circumstellar matter
- Kuiper belt: general
- planetary systems
- planets and satellites: dynamical evolution and stability
- stars: AGB and post-AGB
- white dwarfs
Status
Published
Project
- A unified picture of white dwarf planetary systems
- IMPACT: Comets, asteroids and the habitability of planets
ISBN/ISSN/Other
- ISSN: 0035-8711