Simulations of two-planet systems through all phases of stellar evolution: implications for the instability boundary and white dwarf pollution

By D. Veras, A. Mustill, Amy Bonsor, M. C. Wyatt. 2013

133 citations recorded by the source corpus.

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. (Less)

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/08c574606049d8bb7cb8ee39f26928c72685e400

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In Astronomy and Astrophysics

1. J. Farihi
2. B. Gänsicke
3. D. Koester
4. Amy Bonsor
5. D. Veras
6. Z. Leinhardt
7. J. Almenara
8. D. Pollacco

Citations in the corpus

• One of the closest exoplanet pairs to the 3:2 mean motion resonance: K2-19b and c (2015, methodology): “Veras et al. (2013) outline an algorithm for computing the Hill stability limit; no explicit formula exists for arbitrary eccentricities and inclinations.”
• Circumstellar Debris and Pollution at White Dwarf Stars (2016, background): “Veras et al. (2013) generalized this result for two planetary bodies, demonstrating that instabilities can occur for orbits whose separation exceeds the orbit-crossing (Hill criteria) boundary, and for up to several Gyr into the white dwarf phase (Mustill et al., 2014).”
• The frequency of planetary debris around young white dwarfs (2014, background): “…can and probably do occur as frequent at white dwarfs hotter than≈23 000 K, and dynamically this is actually favored at earlier cooling ages (Debes & Sigurdsson 2002; Bonsor & Wyatt 2011; Veras et al. 2013; Frewen & Hansen 2014), the debris will rapidly sublimate, forming a purely gaseous disc.”
• The Eccentric Kozai-Lidov Effect and Its Applications (2016, background): “…the main sequence, the existence of a companion (either a star, brown dwarf or a planet) can lead to ejection of planets (e.g., Veras and Tout 2012; Veras et al. 2013, 2014) or engulfment of the inner most planet (e.g., Li et al. 2014c; Frewen and Hansen 2015). www.annualreviews.org • The EKL…”
• Formation of planetary debris discs around white dwarfs – I. Tidal disruption of an extremely eccentric asteroid (2014, background): “6 SU M M A RY We have investigated an important step in the process of polluting WDs with circumstellar material: the tidal disruption of bound asteroids which veer into the WD’s Roche radius.”