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Related papers: What is Neptune's D/H ratio really telling us abou…

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Models of core accretion assume that in the radiative zones of accreting gas envelopes, radiation diffuses. But super-Earths/sub-Neptunes (1-4$R_\oplus$, 2-20$M_\oplus$) point to formation conditions that are optically thin: their modest…

Earth and Planetary Astrophysics · Physics 2018-05-16 Eve J. Lee , Eugene Chiang , Jason W. Ferguson

Spectral observations of Neptune made in 2019 with the MUSE instrument at the Very Large Telescope in Chile have been analysed to determine the spatial variation of aerosol scattering properties and methane abundance in Neptune's…

During the million years of evolution, gas dust and ice in protoplanetary disks can be chemically reprocessed. There are evidences that the gas-phase carbon and oxygen abundances are sub-solar in disks belonging to nearby star forming…

Solar and Stellar Astrophysics · Physics 2020-07-01 D. Fedele , C. Favre

Deuterium-to-hydrogen (D/H) enrichments in molecular species provide clues about their original formation environment. The organic materials in primitive solar system bodies have generally higher D/H ratios and show greater D/H variation…

Solar and Stellar Astrophysics · Physics 2016-03-16 L. Ilsedore Cleeves , Edwin A. Bergin , Conel M. O'D. Alexander , Fujun Du , Dawn Graninger , Karin I. Öberg , Tim J. Harries

We discuss our current understanding of the interior structure and thermal evolution of giant planets. This includes the gas giants, such as Jupiter and Saturn, that are primarily composed of hydrogen and helium, as well as the "ice…

Earth and Planetary Astrophysics · Physics 2014-11-20 Jonathan J. Fortney , Nadine Nettelmann

We present a novel python-based 1D sub-Neptune evolution model that emphasizes the thermal evolution and potential solidification of the rock/iron core and the structure of the radiative atmosphere. This model explores planetary structure…

Earth and Planetary Astrophysics · Physics 2025-06-25 Yao Tang , Jonathan J. Fortney , Francis Nimmo , Daniel Thorngren , Kazumasa Ohno , Ruth Murray-Clay

The origins of Uranus and Neptune are not fully understood. Their inclined rotation axes -- obliquities -- suggest that they experienced giant impacts during their formation histories. Simulations modeling their accretion from giant impacts…

Earth and Planetary Astrophysics · Physics 2024-12-05 Leandro Esteves , André Izidoro , Othon C. Winter

The relative abundances of carbon and oxygen have long been recognized as fundamental diagnostics of stellar chemical evolution. Now, the growing number of exoplanet observations enable estimation of these elements in exoplanetary…

Solar and Stellar Astrophysics · Physics 2015-06-19 Johanna K. Teske , Katia Cunha , Verne V. Smith , Simon C. Schuler , Caitlin A. Griffith

We present results from one-dimensional atmospheric simulations investigating the effect of varying the carbon-to-oxygen (C/O) ratio on the thermal structure, chemical composition and transmission and emission spectra, for irradiated…

Earth and Planetary Astrophysics · Physics 2019-04-10 Benjamin Drummond , Aarynn L. Carter , Eric Hébrard , Nathan J. Mayne , David K. Sing , Thomas M. Evans , Jayesh Goyal

In this work we generalize the notion of convective inhibition to apply in cases where there is an infinite reservoir of condensible species (i.e., an ocean). We propose a new model for the internal structure and thermal evolution of…

Earth and Planetary Astrophysics · Physics 2022-09-07 Steve Markham , Dave Stevenson , Tristan Guillot

Complex nitriles, such as HC3N, and CH3CN, are observed in a wide variety of astrophysical environments, including at relatively high abundances in photon-dominated regions (PDR) and the UV exposed atmospheres of planet-forming disks. The…

Earth and Planetary Astrophysics · Physics 2020-01-08 Romane Le Gal , Madison T. Brady , Karin I. Öberg , Evelyne Roueff , Franck Le Petit

The core accretion theory of planet formation has at least two fundamental problems explaining the origins of Uranus and Neptune: (1) dynamical times in the trans-Saturnian solar nebula are so long that core growth can take > 15 Myr, and…

Earth and Planetary Astrophysics · Physics 2015-05-14 Sarah E. Dodson-Robinson , Peter Bodenheimer

New independent constraints on the amount of water delivered to Earth by comets are derived using the 15N/14N isotopic ratio, measured to be roughly twice as high in cometary CN and HCN as in the present Earth. Under reasonable assumptions,…

Earth and Planetary Astrophysics · Physics 2015-05-13 D. Hutsemekers , J. Manfroid , E. Jehin , C. Arpigny

The standard solar model was so reliable that it could predict the existence of the massive neutrino. Helioseismology measurements were so precise that they could determine the depth of the convection zone. This agreement between theory and…

Astrophysics · Physics 2009-11-13 J. T. Schmelz , K. Nasraoui , J. K. Roames , L. A. Lippner , J. W. Garst

Probing the interiors of the gas giant planets in our Solar System is not an easy task. It requires a set of accurate measurements combined with theoretical models that are used to infer the planetary composition and its depth dependence.…

Earth and Planetary Astrophysics · Physics 2018-12-19 Ravit Helled

The presence of N2 in the surface environment of Pluto is critical in creating Pluto's richness of features and processes. Here, we propose that the nitrogen atoms in the N2 observed on Pluto were accreted in that chemical form during the…

Earth and Planetary Astrophysics · Physics 2018-05-29 Christopher R. Glein , J. Hunter Waite

Recent analyses of the orbits of some Kuiper Belt objects hypothesize the presence of an undiscovered Neptune-size planet at a very large separation from the Sun. The energy budget of Neptunes on such distant orbits is dominated by the…

Earth and Planetary Astrophysics · Physics 2016-05-04 Sivan Ginzburg , Re'em Sari , Abraham Loeb

Formation of planets in the Neptune size range with low-mass, but voluminous, H_2/He gaseous envelopes is modeled by detailed numerical simulations according to the core-nucleated accretion scenario. Formation locations ranging from 0.5 to…

Earth and Planetary Astrophysics · Physics 2015-06-22 Peter Bodenheimer , Jack J. Lissauer

We present 'empirical' models (pressure vs. density) of Saturn's interior constrained by the gravitational coefficients J_2, J_4, and J_6 for different assumed rotation rates of the planet. The empirical pressure-density profile is…

Astrophysics · Physics 2009-11-13 Ravit Helled , Gerald Schubert , John D. Anderson

We have investigated the information content in reflected-starlight spectra of exoplanets. We specify our analysis to Barnard's Star b candidate super-Earth, for which we assume a radius 0.6 times that of Neptune, an atmosphere dominated by…

Earth and Planetary Astrophysics · Physics 2020-09-02 Óscar Carrión-González , Antonio García Muñoz , Juan Cabrera , Szilárd Csizmadia , Nuno C. Santos , Heike Rauer
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