Superabundance of Exoplanet Sub-Neptunes Explained by Fugacity Crisis

Edwin S. Kite, Fegley Bruce Fegley, Laura Schaefer, Eric B. Ford

Research output: Contribution to journalArticle

Abstract

Transiting planets with radii 2-3 R are much more numerous than larger planets. We propose that this drop-off is so abrupt because at R ∼ 3 R base-of-atmosphere pressure is high enough for the atmosphere to readily dissolve into magma, and this sequestration acts as a strong brake on further growth. The viability of this idea is demonstrated using a simple model. Our results support extensive magma-atmosphere equilibration on sub-Neptunes, with numerous implications for sub-Neptune formation and atmospheric chemistry.

Original languageEnglish (US)
Article numberL33
JournalAstrophysical Journal Letters
Volume887
Issue number2
DOIs
StatePublished - Dec 20 2019

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All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

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