Orbit classification in exoplanetary systems
Abstract
The circular version of the restricted threebody problem, along with the method of grid classification are used to determine the character of the trajectories of a test particle, which move in a binary exoplanetary system. The binary system can be either a parent starexoplanet or an exoplanetexoplanet or exomoon, while the test particle is considered to be an asteroid or comet, a space probe, or even a small exomoon in the case where the primary body is a star. By using modern twodimensional color maps, we succeeded in classifying the starting conditions and distinguishing between bounded, escaping, and collision type of motion for the test particle. Furthermore, in the case of bounded regular motion, we further classify the starting conditions by considering their geometry (revolving around one or both main bodies) and orientation (prograde or retrograde, with respect to a rotating coordinate system of the primaries). For the initial setup of the test particle we consider two starting conditions: the launch from pericenter or apocenter. The final states are qualitatively visualized through twodimensional basin diagrams. This approach allowed us to systematically investigate and extract dynamical information on the dependency of the test particle final state as a function of the particle's initial semimajor axis and eccentricity for a given primary and secondary mass ratio. Finally, we applied the restricted threebody model on several exoplanetary systems with observed massratios and studied the dynamical behavior of a testmass.
 Publication:

Astronomy and Astrophysics
 Pub Date:
 February 2020
 DOI:
 10.1051/00046361/201937224
 Bibcode:
 2020A&A...634A..60Z
 Keywords:

 methods: numerical;
 celestial mechanics