Uranus and Neptune are reinterpreted as magma-ocean giants with hydrogen-rich interiors rather than traditional ice giants, consistent with observations via three fit parameters each.
The Influences of Hydrogen-Silicate-Iron Miscibility on the Demographics of Sub-Neptunes and Super-Earths
5 Pith papers cite this work. Polarity classification is still indexing.
abstract
Models based on variable miscibility among hydrogen, molten silicate, and molten iron, coupled with atmospheric escape, can reproduce the observed occurrence density structure of sub-Neptunes and super-Earths in mass-radius space. The models are also consistent with the radius gap and the observed radius-period relationship exhibited by these planets. The degree of overlap between predicted and observed planetary occurrences suggests that hydrogen-silicate-iron miscibility may serve as a unifying concept for the formation and evolution of these planet classes. The well-defined equilibrium conditions at the boundary between supercritical magma oceans and the overlying hydrogen-rich envelopes are important features of the models. Planets formed with less than ~1 % hydrogen by mass develop discrete, terrestrial-like metallic cores, while those accreting greater hydrogen concentrations are predicted to have fully miscible interiors and no discrete metal cores. Hydrogen-silicate-iron miscibility provides an overarching explanation for the full range of sub-Neptune and super-Earth architectures based on the accreted hydrogen mass fraction and the phase equilibria governing silicate, iron metal, and H$_2$ miscibility.
fields
astro-ph.EP 5years
2026 5representative citing papers
An open-source GCE code with a 100x faster solver demonstrates that refractory ratios Mg/Si and Fe/Si control carbon partitioning and atmospheric properties in water-accreting sub-Neptunes.
Water-rich formation produces CH4- and CO2-rich atmospheres while water-poor formation produces carbon-depleted ones, with soot boosting methane; the H2O/CH4-MMW plane diagnoses formation environment for JWST targets.
Coupling Bern formation models with extended chemical equilibrium including S and N shows equilibration depletes atmospheric nitrogen, shifts C/O higher outside the ice line, generates Si species, and leaves sulfur abundances weakly dependent on formation location.
Hydrogen-silicate miscibility stores hydrogen in sub-Neptune interiors, resupplies escaping envelopes, delays contraction, matches young-planet observations, and enables a population test requiring 70-100 targets under 100 Myr.
citing papers explorer
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Ice Giants Revisited: Uranus and Neptune as Magma Ocean Worlds
Uranus and Neptune are reinterpreted as magma-ocean giants with hydrogen-rich interiors rather than traditional ice giants, consistent with observations via three fit parameters each.
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A New Global Chemical Equilibrium Code: Refractory Element Signatures in Super-Earths and Sub-Neptunes
An open-source GCE code with a 100x faster solver demonstrates that refractory ratios Mg/Si and Fe/Si control carbon partitioning and atmospheric properties in water-accreting sub-Neptunes.
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Atmospheric diversity of sub-Neptunes from formation with rock, water, and soot
Water-rich formation produces CH4- and CO2-rich atmospheres while water-poor formation produces carbon-depleted ones, with soot boosting methane; the H2O/CH4-MMW plane diagnoses formation environment for JWST targets.
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The Role of Formation Location in Shaping Sulfur-, Nitrogen-, and Carbon-Bearing Species in Super-Earth and Sub-Neptune Atmospheres
Coupling Bern formation models with extended chemical equilibrium including S and N shows equilibration depletes atmospheric nitrogen, shifts C/O higher outside the ice line, generates Si species, and leaves sulfur abundances weakly dependent on formation location.
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Testing the prevalence of hydrogen-silicate miscibility in young sub-Neptunes
Hydrogen-silicate miscibility stores hydrogen in sub-Neptune interiors, resupplies escaping envelopes, delays contraction, matches young-planet observations, and enables a population test requiring 70-100 targets under 100 Myr.