Stability of Multiple Planetary Systems |
TYPE | Astrophysics Seminar |
Speaker: | Alice Quillen |
Affiliation: | Rochester University |
Organizer: | Hagai Perets |
Date: | 01.01.2013 |
Time: | 15:30 - 16:30 |
Location: | Lidow 605 |
Abstract: | Multiple planet and satellite systems are affected by three-body and secular resonances affecting short timescale behavior and long timescale stability. I will discuss theoretical scenarios that account for stability timescales measured numerically for closely spaced planetary systems, such as closely spaced Kepler multiple planet systems and the Uranian satellite system. Three-body resonances, constructed of two non-resonant zero-th order two-body terms are sufficiently dense to account for wander in semi-major axis seen in numerical integrations of some closely spaced systems and they are likely the cause of instability of these systems. A resonance overlap criterion is derived with three-body resonances overlapping when interplanetary separation is less than an order unity factor times the planet mass to the one quarter power. This represents a first attempt to account for numerically measured stability times in closely spaced multiple planet systems. When systems are in low order two-body resonances, stability timescales can be either reduced or increased. I will also discuss the capture and stability of systems in resonant chains, where each consecutive pair of bodies is in or near a low order two-body resonance, such as inferred in the HR8799 and KOI 730 planetary systems. |