On the formation of super-Jupiters: core accretion or gravitational instability?

• Published in: Astrophysics and space science Vol. 369; no. 12; p. 122
• Main Authors: Nguyen, Max, Adibekyan, Vardan
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.12.2024; Springer Nature B.V
• Subjects: Accretion; Accretion disks; Astrobiology; Astronomy; Astrophysics and Astroparticles; Building materials; Cosmology; Extrasolar planets; Gas giant planets; Gravitational instability; Jupiter; Jupiter atmosphere; Metal content; Metallicity; Observations and Techniques; Physics; Physics and Astronomy; Planet formation; Planetary composition; Planetary mass; Planets; Protoplanetary disks; Space Exploration and Astronautics; Space Sciences (including Extraterrestrial Physics; Stellar atmospheres; Stellar mass; Stellar mass accretion; Chemical abundances; Exoplanet formation; Planet hosting stars; Methods: statistical
• ISSN: 0004-640X; 1572-946X
• DOI: 10.1007/s10509-024-04388-2

The Core Accretion model is widely accepted as the primary mechanism for forming planets up to a few Jupiter masses. However, the formation of super-massive planets remains a subject of debate, as their formation via the Core Accretion model requires super-solar metallicities. Assuming stellar atmospheric abundances reflect the composition of protoplanetary disks, and that disk mass scales linearly with stellar mass, we calculated the total amount of metals in planet-building materials that could contribute to the formation of massive planets. In this work, we studied a sample of 172 Jupiter-mass planets and 93 planets with masses exceeding 4 M ♃ . Our results consistently demonstrate that planets with masses above 4 M ♃ form in disks with at least as much metal content as those hosting planets with masses between 1 and 4 M ♃ , often with slightly higher metallicity, typically exceeding that of the proto-solar disk. We interpret this as strong evidence that the formation of very massive Jupiters is feasible through Core Accretion and encourage planet formation modelers to test our observational conclusions.