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Related papers: Hydrogen-helium immiscibility boundary in planets

200 papers

As a contribution to the study of the habitability of extrasolar planets, we implemented a 1-D Energy Balance Model (EBM), the simplest seasonal model of planetary climate, with new prescriptions for most physical quantities. Here we apply…

Earth and Planetary Astrophysics · Physics 2015-06-15 Giovanni Vladilo , Giuseppe Murante , Laura Silva , Antonello Provenzale , Gaia Ferri , Gregorio Ragazzini

The formation of the giant planets in our solar system, and likely a majority of giant exoplanets, is commonly explained by the accretion of nebular hydrogen and helium onto a large core of terrestrial-like composition. The fate of this…

Earth and Planetary Astrophysics · Physics 2015-06-15 Sean Wahl , Hugh F. Wilson , Burkhard Militzer

Recent laser-shock experiments on an H--He mixture containing 11~$\%$ helium (atomic fraction) have suggested the presence of an immiscibility region inside Jupiter. Reflectivity measurements were used as the primary diagnostic of H--He…

Other Condensed Matter · Physics 2026-05-05 Ammar A. Ellaboudy , Valentin V. Karasiev , S. X. Hu

The internal structures of Uranus and Neptune remain unknown. In addition, sub-Neptunes are now thought to be the most common type of exoplanets. Understanding the physical processes that govern the interiors of such planets is therefore…

Earth and Planetary Astrophysics · Physics 2025-11-19 Saburo Howard , Ravit Helled , Armin Bergermann , Ronald Redmer

Ultra-hot Jupiters (UHJs) have recently been the focus of several atmospheric studies due to their extreme properties. While molecular hydrogen (H$_2$) plays a key role in UHJ atmospheres, it has not been directly detected on an exoplanet.…

Earth and Planetary Astrophysics · Physics 2022-07-14 Anastasia Morgan , P. Wilson Cauley , Kevin France , Allison Youngblood , Tommi T. Koskinen

Most of the molecules detected thus far in exoplanet atmospheres, such as water and CO, are present for a large range of pressures and temperatures. In contrast, metal hydrides exist in much more specific regimes of parameter space, and so…

Earth and Planetary Astrophysics · Physics 2020-11-04 Aurora Kesseli , I. A. G. Snellen , F. J. Alonso-Floriano , P. Molliere , D. B. Serindag

The increasing number of detailed exoplanet observations offers an opportunity to refine our analyses and interpretations. Here, we show that atmospheres that appear volatile-rich and/or cloudy may instead be helium-rich. As transmission…

Earth and Planetary Astrophysics · Physics 2026-01-07 Julien de Wit , Aaron Householder , Prajwal Niraula

We present and test chemical models for three-dimensional hydrodynamical simulations of galaxies. We explore the effect of changing key parameters such as metallicity, radiation and non-equilibrium versus equilibrium metal cooling…

Astrophysics of Galaxies · Physics 2016-05-04 Stefano Bovino , Tommaso Grassi , Pedro R. Capelo , Dominik R. G. Schleicher , R. Banerjee

The assumption of a spatially uniform helium distribution in the intracluster medium can lead to biases in the estimates of key cluster parameters if composition gradients are present. The helium concentration profile in galaxy clusters is…

High Energy Astrophysical Phenomena · Physics 2020-06-04 Thomas Berlok , Martin E. Pessah

Many sub-Neptune exoplanets have been believed to be composed of a thick hydrogen-dominated atmosphere and a high-temperature heavier-element-dominant core. From an assumption that there is no chemical reaction between hydrogen and…

Earth and Planetary Astrophysics · Physics 2024-01-08 Taehyun Kim , Xuehui Wei , Stella Chariton , Vitali B. Prakapenka , Young-Jay Ryu , Shize Yang , Sang-Heon Shim

The near-infrared helium triplet line is a powerful tool for studying atmospheric escape processes of close-in exoplanets, especially irradiated gas giants. Line profile fitting provides direct insight into the mechanisms driving…

We show that collision-induced absorption allows molecular hydrogen to act as an incondensible greenhouse gas, and that bars or tens of bars of primordial H2-He mixtures can maintain surface temperatures above the freezing point of water…

Earth and Planetary Astrophysics · Physics 2015-05-28 Raymond Pierrehumbert , Eric Gaidos

More than two dozen short-period Jupiter-mass gas giant planets have been discovered around nearby solar-type stars in recent years, several of which undergo transits, making them ideal for the detection and characterization of their…

Astrophysics · Physics 2009-11-13 Ian Dobbs-Dixon , D. N. C. Lin

Atomic hydrogen (HI) serves a crucial role in connecting galactic-scale properties such as star formation with the large-scale structure of the Universe. While recent numerical simulations have successfully matched the observed covering…

Astrophysics of Galaxies · Physics 2024-07-16 Lucas Tortora , Robert Feldmann , Mauro Bernardini , Claude-André Faucher-Giguère

Hydrodynamic outflows, such as those observed escaping close-in gas giant planets, are not isothermal in structure. Their highly ionized nature allows them to cool adiabatically at distances beyond several planetary radii. The contrast…

Earth and Planetary Astrophysics · Physics 2025-05-21 Matthäus Schulik , James Owen

In this paper we investigate the level of hydrostatic equilibrium (HE) in the intra-cluster medium of simulated galaxy clusters, extracted from state-of-the-art cosmological hydrodynamical simulations performed with the…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-24 V. Biffi , S. Borgani , G. Murante , E. Rasia , S. Planelles , G. L. Granato , C. Ragone-Figueroa , A. M. Beck , M. Gaspari , K. Dolag

Seven temperate Earth-sized exoplanets readily amenable for atmospheric studies transit the nearby ultracool dwarf star TRAPPIST-1 (refs 1,2). Their atmospheric regime is unknown and could range from extended primordial hydrogen-dominated…

Planets with masses between Earth and Neptune often have radii that imply the presence of volatiles, suggesting that water may be abundant in their interiors. However, directly observing the precise water mass fraction and water…

Earth and Planetary Astrophysics · Physics 2026-01-08 Michael Lozovsky

In anticipation of new observational results for Jupiter's axial moment of inertia and gravitational zonal harmonic coefficients from the forthcoming Juno orbiter, we present a number of preliminary Jupiter interior models. We combine…

Earth and Planetary Astrophysics · Physics 2016-04-06 W. B. Hubbard , B. Militzer

Anomalous features for hypothetical Plasma Phase Transitions (PPT), which is expected to occur in mixed hydrogen-helium plasma in interior of Jupiter and Saturn, are under discussion. The characteristics of the Coulomb and density…

Plasma Physics · Physics 2013-12-31 Artem Ukrainets , Igor Iosilevskiy