Dynamical Aspects of Exoplanetary Systems
Abstract
The detection of more than 130 multiple planet systems makes it necessary to interpret
a broader range of properties than are shown by our Solar system. This thesis covers
aspects linked to the proliferation in recent years of multiple extrasolar planet systems.
A narrow observational window, only partially covering the longest orbital period,
can lead to solutions representing unrealistic scenarios. The best-fit solution for the
three-planet extrasolar system of HD 181433 describes a highly unstable configuration.
Taking into account the dynamical stability as an additional observable while interpreting
the RV data, I have analysed the phase space in the neighbourhood of the statistical
best-fit. The two giant companions are found to be locked in the 5:2 MMR in the stable
best-fit model.
I have analysed the dynamics of the system HD 181433 by assessing different scenarios
that may explain the origin of these eccentric orbits, with particular focus on the
innermost body. A scenario is considered in which the system previously contained an
additional giant planet that was ejected during a period of dynamical instability among
the planets. Also considered is a scenario in which the spin-down of the central star
causes the system to pass through secular resonance. In its simplest form this latter scenario
fails to produce the system observed. If additional short-period low mass planets
are present in the system, I find that mutual scattering can release planet b from the secular
resonance, leading to a system with orbital parameters similar to those observed
today.
Finally, I have studied the evolution of low mass planets interacting with a gas-giant
planet embedded in a gaseous disc. The transit timing method allows the detection
of non-transiting planets through their gravitational perturbations. I have investigated
the detectability of low mass planets neighbouring short-period giants after protoplanetary
disc dispersal.
Authors
Campanella, GiammarcoCollections
- Theses [4125]