Formation of gas giant planets

Core accretion models with fragmentation and planetary envelope

Satoshi Inaba, G. W. Wetherill, M. Ikoma

Research output: Contribution to journalArticle

103 Citations (Scopus)

Abstract

We have calculated formation of gas giant planets based on the standard core accretion model including effects of fragmentation and planetary envelope. The accretion process is found to proceed as follows. As a result of runaway growth of planetesimals with initial radii of ∼ 10 km, planetary embryos with a mass of ∼ 1027 g (∼ Mars mass) are found to form in ∼ 105 years at Jupiter's position (5.2 AU), assuming a large enough value of the surface density of solid material (25 g/cm2) in the accretion disk at that distance. Strong gravitational perturbations between the runaway planetary embryos and the remaining planetesimals cause the random velocities of the planetesimals to become large enough for collisions between small planetesimals to lead to their catastrophic disruption. This produces a large number of fragments. At the same time, the planetary embryos have envelope, that reduce energies of fragments by gas drag and capture them. The large radius of the envelope increases the collision rate between them, resulting in rapid growth of the planetary embryos. By the combined effects of fragmentation and planetary envelope, the largest planetary embryo with 21M forms at 5.2 AU in 3.8 × 106 years. The planetary embryo is massive enough to start a rapid gas accretion and forms a gas giant planet.

Original languageEnglish
Pages (from-to)46-62
Number of pages17
JournalIcarus
Volume166
Issue number1
DOIs
Publication statusPublished - 2003 Nov
Externally publishedYes

Fingerprint

gas giant planets
embryos
embryo
fragmentation
envelopes
protoplanets
planet
planetesimal
accretion
gas
collision
fragments
collision rates
radii
Jupiter (planet)
gases
accretion disks
Jupiter
mars
drag

Keywords

  • Atmospheres
  • Jovian planets
  • Origin
  • Planetary formation
  • Planetesimals
  • Solar System
  • Structure

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Formation of gas giant planets : Core accretion models with fragmentation and planetary envelope. / Inaba, Satoshi; Wetherill, G. W.; Ikoma, M.

In: Icarus, Vol. 166, No. 1, 11.2003, p. 46-62.

Research output: Contribution to journalArticle

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