Dynamics and Accretion of Planetesimals

Abstract

We review the basic dynamics and accretion of planetesimals by showing N-body simulations. The orbits of planetesimals evolve through two-body gravitational relaxation: viscous stirring increases the random velocity and dynamical friction realizes the equiparation of the random energy. In the early stage of planetesimal accretion the growth mode of planetesimals is runaway growth where larger planetesimals grow faster than smaller ones. When a protoplanet (runaway-growing planetesimal) exceeds a critical mass the growth mode shifts to oligarchic growth where similar-sized protoplanets grow keeping a certain orbital separation. The final stage of terrestrial planet formation is collision among protoplanets known as giant impacts. We also summarize the dynamical effects of disk gas on planets and the core accretion model for formation of gas giants and discuss the diversity of planetary systems.

References in corpus (3)

• Toward a Deterministic Model of Planetary Formation V. Accumulation Near the Ice Line
• Constraints on the mass of a habitable planet with water of nebular origin
• Infall of planetesimals onto growing giant planets: onset of runaway gas accretion and metallicity of their gas envelopes

Cited by in corpus (8)

• Kuiper Belt-Like Hot and Cold Populations of Planetesimal Inclinations in the $\beta$ Pictoris Belt Revealed by ALMA
• Heavy-metal Jupiters by major mergers: metallicity vs. mass for giant planets
• Chemistry Along Accretion Streams in a Viscously-Evolving Protoplanetary Disk
• Composition constraints of the TRAPPIST-1 planets from their formation
• Formation of inner planets in the presence of a Cold Jupiter: orbital evolution and relative velocities of planetesimals
• Planetesimal Dynamics in the Presence of a Giant Planet
• Planetesimal Dynamics in the Presence of a Giant Planet II: Dependence on Planet Mass and Eccentricity
• Runaway Growth of Planetesimals Revisited: Presenting Criteria Required for Realistic Modeling of Planetesimal Growth