Planetary System from the Outer Edge of the Inner Void -- Classes and Populations of Variety

TL;DR

This paper proposes a dynamical model for planet formation involving dust accumulation at the inner void of protoplanetary disks, explaining the diversity of planetary types and populations observed.

Contribution

It introduces a novel planet formation model based on dust fall, accumulation, and slingshot processes at the disk's inner edge, without relying on specific physical origins of the void.

Findings

Formation of first-generation Hot-Jupiters at the inner edge.

Diverse planetary populations including rocky, gas, and ice giants.

Planet population diagram explaining variety and stray planets.

Abstract

Planets are common objects in the Universe, observationally as well as theoretically. However, the standard theory of their formation encounters many difficulties, such as dust fall and disk lifetime problems. We positively analyze them, expecting that those problems as a whole may indicate some consistent effective model. Thus we propose a dynamical model of the planet formation based on the assumption that the inner void of gas is commonly formed in the disk without specifying any Physical origin. The basic processes of this model are the dust fall, the accumulation, and the slingshots. The dust in the protoplanetary disk rapidly falls as it grows to the meter size. Then, all of them stops at the outer edge of the void where the gas friction disappears. Such dust clusters rapidly coalesce with each other and easily cause the runaway in the dense and coherent environment. Then the huge clusters are formed there and they are the first generation planets Hot-Jupiters. They immediately slingshot smaller clusters around them towards the outer regions. They are Rockey-Planets, Cold-Gas-Giants, Ice-Giants, and `Trans Neptunian objects including `Kuiper belt/Oort cloud objects`, depending on the original core mass or the distance blown. Combining numerical calculations of the slingshots and coagulation equations, we obtain the planet population diagram, including the possibility of the massive thermal metamorphosis, the origin of the variety of planetary systems, and the possibility of stray planets/objects.