Evolution of angular-momentum-losing exoplanetary systems - Revisiting Darwin stability
Abstract
The dynamical evolution of planetary systems, after the evaporation of the accretion disk, is the result of the competition between tidal dissipation and the net angular momentum loss of the system. In the case of multiple systems, gravitational interaction between planets must also be taken into account. However, even focusing on single companion systems, the description of the diversity of orbital configurations, and correlations between parameters of the observed system, (e.g. in the case of hot Jupiters) is still limited by our understanding of tidal dissipation and its interplay with magnetic braking.Using energy considerations only, I will present a new characterisation of the tidal equilibrium that is valid when the total angular momentum of the system is not conserved. This implies a remarkably different evolution of the planet's semi-major axis depending on the properties of the stellar host. I apply this theory to a sample of planetary systems and discuss their evolution using a particularly simple graphic approach that generalizes the classic Darwin tidal diagrams. This can help constraining theories of tidal dissipation and testing models of planetary formation. This kind of studies rely on the determination of stellar raddi, masses and ages. Major advances will thus be obtained with the results of the PLATO 2.0 mission, selected as the next M-class mission of ESA's Cosmic Vision plan, that will allow the complete characterization of host stars using asteroseismology.
- Publication:
-
AAS/Division for Extreme Solar Systems Abstracts
- Pub Date:
- December 2015
- Bibcode:
- 2015ESS.....310906D