Author 1: Oleynik O.S., Emelyanenko V. V. (INASAN)

Title: Migration of Earth-like Planets in Planetesimal Disks and the Formation of Debris Disks

Abstracts:
We investigate the interaction between Earth-mass planets and a planetesimal disk. It is shown that a planet initially located near the inner edge of a planetesimal disk migrates inward into the disk. The depth of the planet’s penetration is determined by the angular-momentum distribution of the planetesimals that encounter it. The direction of migration always reverses, and the planet returns to the disk’s inner edge. During this reversible migration, the planet reshapes planetesimal orbits and increases their mutual relative velocities within the region it traverses. The relative velocities rise to values sufficient for collisional fragmentation. We show that after an Earth-mass planet passes through the outer planetesimal disk, the mean relative velocities over most of the disk reach levels high enough to fragment monolithic basaltic planetesimals up to ~40 km in size. Thus, the interaction of even a relatively small planet (of order an Earth mass) with a planetesimal disk can generate dust particles that are observable in outer debris disks.

Author 2: Emelyanenko V. V. (INASAN)

Title: Distant Trans-Neptunian Objects in a Solar System with Additional Outer Planets

Abstracts:
We discuss the origin of distant trans-Neptunian objects (TNOs) in systems that include the known giant planets, additional outer planets, and massive planetesimals. The study is based on N-body integrations over timescales comparable to the age of the Solar System. First, we analyze Solar-System evolutions with additional Earth-mass planets; second, we consider systems with more massive additional planets. In most numerical realizations the planetary systems are either disrupted or evolve onto orbits that differ substantially from the present ones. Nevertheless, we find many cases in which the systems survive for the Solar-System lifetime with configurations close to the current architecture. Such systems are characterized by populations of distant TNOs whose dynamical behaviors are diverse and include mutual secular resonances and close encounters. The combined perturbations from the giant planets, the additional planets, and the self-gravity of the planetesimal disk produce distant TNOs on both highly eccentric and nearly circular orbits. We note a trend toward larger numbers of surviving distant TNOs as the number of additional planets increases.