Orbital stability of compact three-planets systems spaced non-uniformly
Abstract
Recent discoveries unveiled a significant number of compact multi-planetary systems, where the adjacent planets orbits are much closer to those found in the Solar System. For instance, the recently found system TRAPPIST-1 harbors seven planets all orbiting within 0.1 AU from their host star. Studying the orbital stability of such compact systems provides how they form and how long they survive. Most previous investigations of compact systems have been done for planets that are equally-spaced in terms of their mutual Hill radius. We performed a more general study of three Earth-like planets orbiting a Sun-mass star in circular and coplanar prograde orbits. We first recover the results of previous studies done for systems of planets spaced uniformly in mutual Hill radius. We have simulated over 500 systems with different initial spacing between the adjacent inner pair of planets and the outer pair of planets and we displayed their lifetime on a grid. We performed the simulations over a wide range of mutual Hill radii. The simulations were conducted for virtual times reaching at most 4 billion years. We characterize isochrones for lifetime of systems of equivalent spacing. We find that the stability time increases significantly for values of mutual Hill radii beyond 8. We also study the affects of mean motion resonances and the degree of symmetry in the grid.
- Publication:
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AAS/Division for Planetary Sciences Meeting Abstracts #49
- Pub Date:
- October 2017
- Bibcode:
- 2017DPS....4950601G