2015/11/30 by Daniel P. Thorngren, Daniel Thorngren, Jonathan J. Fortney +4 · 3 citations
Physics and Astronomy · #Astro and Planetary Science #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Exoplanet #Giant planet #Heavy element #Metallicity #Physics #Planet #Planetary mass #Planetary migration #Planetary system #RADIUS #Star (game theory) #Star formation #Stars #Stellar mass #Stellar, planetary, and galactic studies #astro-ph.EP
paper · pdf · doi:10.3847/0004-637x/831/1/64
Accepted to The Astrophysical Journal. This revision adds a substantial amount of discussion; the results are the same
arxiv created 2016/08/31 · openalex publication_date 2016/10/27 · arxiv updated 2016/11/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
ABSTRACT Exoplanet discoveries of recent years have provided a great deal of new data for studying the bulk compositions of giant planets. Here we identify 47 transiting giant planets (20 M ⊕ < M < 20 M J ) whose stellar insolations are low enough ( F * < 2 × 10 8 erg s −1 cm −2 , or roughly T eff < 1000) that they are not affected by the hot-Jupiter radius inflation mechanism(s). We compute a set of new thermal and structural evolution models and use these models in comparison with properties of the 47 transiting planets (mass, radius, age) to determine their heavy element masses. A clear correlation emerges between the planetary heavy element mass M z and the total planet mass, approximately of the form . This finding is consistent with the core-accretion model of planet formation. We also study how stellar metallicity [Fe/H] affects planetary metal-enrichment and find a weaker correlation than has previously been reported from studies with smaller sample sizes. We confirm a strong relationship between the planetary metal-enrichment relative to the parent star Z planet / Z star and the planetary mass, but see no relation in Z planet / Z star with planet orbital properties or stellar mass. The large heavy element masses of many planets (>50 M ⊕ ) suggest significant amounts of heavy elements in H/He envelopes, rather than cores, such that metal-enriched giant planet atmospheres should be the rule. We also discuss a model of core-accretion planet formation in a one-dimensional disk and show that it agrees well with our derived relation between mass and Z planet / Z star .