Composition of Massive Giant Planets

TL;DR

This paper compares core accretion and disk instability models for giant planet formation, highlighting their predictions for planetary composition and enrichment, and discussing the uncertainties in final planetary structures.

Contribution

It provides a comparative analysis of formation models, emphasizing their ability to produce a wide range of planetary compositions and the challenges in constraining planetary structure.

Findings

Both models can produce planets with nearly stellar compositions.

Low-mass giant planets are more consistent with core accretion.

Final heavy element distribution remains uncertain in both models.

Abstract

The two current models for giant planet formation are core accretion and disk instability. We discuss the core masses and overall planetary enrichment in heavy elements predicted by the two formation models, and show that both models could lead to a large range of final compositions. For example, both can form giant planets with nearly stellar compositions. However, low-mass giant planets, enriched in heavy elements compared to their host stars, are more easily explained by the core accretion model. The final structure of the planets, i.e., the distribution of heavy elements, is not firmly constrained in either formation model.