Alexander Mustill
Researcher
Simulations of two-planet systems through all phases of stellar evolution: implications for the instability boundary and white dwarf pollution
Author
Summary, in English
Exoplanets have been observed at many stages of their host star's life, including the main-sequence (MS), subgiant and red giant branch stages. Also, polluted white dwarfs (WDs) likely represent dynamically active systems at late times. Here, we perform three-body simulations which include realistic post-MS stellar mass-loss and span the entire lifetime of exosystems with two massive planets, from the endpoint of formation to several Gyr into the WD phase of the host star. We find that both MS and WD systems experience ejections and star-planet collisions (Lagrange instability) even if the planet-planet separation well-exceeds the analytical orbit-crossing (Hill instability) boundary. Consequently, MS-stable planets do not need to be closely packed to experience instability during the WD phase. This instability may pollute the WD directly through collisions, or, more likely, indirectly through increased scattering of smaller bodies such as asteroids or comets. Our simulations show that this instability occurs predominately between tens of Myr to a few Gyr of WD cooling.
Publishing year
2013
Language
English
Pages
1686-1708
Publication/Series
Monthly Notices of the Royal Astronomical Society
Volume
431
Issue
2
Document type
Journal article
Publisher
Oxford University Press
Topic
- Physical Sciences
- Astronomy, Astrophysics and Cosmology
Keywords
- Astrophysics - Earth and Planetary Astrophysics
- Astrophysics - Solar and Stellar Astrophysics
- planet-star interactions
- planets and satellites: dynamical evolution and stability
- stars: AGB and post-AGB
- stars: evolution
- white dwarfs
Status
Published
ISBN/ISSN/Other
- ISSN: 1365-2966