The Fuzziness of Giant Planets’ Cores

Journal Article · Mon May 01 04:00:00 EDT 2017 · Astrophysical Journal Letters

DOI:https://doi.org/10.3847/2041-8213/AA6D08· OSTI ID:22654489

Helled, Ravit ^[1]; Stevenson, David ^[2]

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1. Institute for Computational Science, University of Zurich, Zurich (Switzerland)
2. Division of Geological and Planetary Sciences, Caltech, Pasadena, CA (United States)

Giant planets are thought to have cores in their deep interiors, and the division into a heavy-element core and hydrogen–helium envelope is applied in both formation and structure models. We show that the primordial internal structure depends on the planetary growth rate, in particular, the ratio of heavy elements accretion to gas accretion. For a wide range of likely conditions, this ratio is in one-to-one correspondence with the resulting post-accretion profile of heavy elements within the planet. This flux ratio depends sensitively on the assumed solid-surface density in the surrounding nebula. We suggest that giant planets’ cores might not be distinct from the envelope and includes some hydrogen and helium, and the deep interior can have a gradual heavy-element structure. Accordingly, Jupiter’s core may not be well defined. Accurate measurements of Jupiter’s gravitational field by Juno could put constraints on Jupiter’s core mass. However, as we suggest here, the definition of Jupiter’s core is complex, and the core’s physical properties (mass, density) depend on the actual definition of the core and on the planet’s growth history.

• OSTI ID: 22654489
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 1 Vol. 840; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
DENSITY
GRAVITATIONAL FIELDS
HELIUM
HYDROGEN
JUPITER PLANET
LIMITING VALUES
MASS
NEBULAE
SATELLITES