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Related papers: On stable H-C-N-O compounds at high pressure

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Gas-giant exoplanets are test cases for theories of planet formation as their atmospheres are proposed to carry signatures of their formation within the protoplanetary disk. The metallicity and C/O are key diagnostics, allowing to…

Earth and Planetary Astrophysics · Physics 2025-08-14 Catherine Walsh

It is now understood that the accretion of terrestrial planets naturally involves giant collisions, the moon-forming impact being a well known example. In the aftermath of such collisions the surface of the surviving planet is very hot and…

Hydrogen, helium, silicates, and iron are key building blocks of rocky and gas-rich planets, yet their chemical interactions remain poorly constrained. Using first-principles molecular dynamics and thermodynamic integration, we quantify…

Earth and Planetary Astrophysics · Physics 2025-10-30 Akash Gupta , Haiyang Luo , Jie Deng , Adam Burrows

A primary goal of characterizing exoplanet atmospheres is to constrain planetary bulk properties, such as their metallicity, C/O ratio, and intrinsic heat. However, there are significant uncertainties in many aspects of atmospheric physics,…

Earth and Planetary Astrophysics · Physics 2024-10-23 Sagnick Mukherjee , Jonathan J. Fortney , Nicholas F. Wogan , David K. Sing , Kazumasa Ohno

Uranus and Neptune, the so-called "ice giants", represent a fascinating class of planets. They are the outermost planets in the solar system with intermediate masses/sizes, complex non-polar magnetic fields, strong atmospheric winds, and…

Earth and Planetary Astrophysics · Physics 2025-04-28 Ravit Helled

(Abridged) Near- to mid-IR observations of protoplanetary disks show that the inner regions (<10AU) are rich in small organic volatiles (e.g., C2H2 and HCN). Trends in the data suggest that disks around cooler stars (~3000K) are potentially…

Earth and Planetary Astrophysics · Physics 2016-08-08 Catherine Walsh , Hideko Nomura , Ewine F. van Dishoeck

The material in planet-forming disks determines the composition of planets; hence, it is crucial to understand the physical and chemical processes that set the abundance and distribution of key volatiles. James Webb Space Telescope…

Earth and Planetary Astrophysics · Physics 2026-03-09 Javiera K. Díaz-Berríos , Catherine Walsh , Ewine F. van Dishoeck

Many parameters constraining the spectral appearance of exoplanets are still poorly understood. We therefore study the properties of irradiated exoplanet atmospheres over a wide parameter range including metallicity, C/O ratio and host…

Earth and Planetary Astrophysics · Physics 2015-11-04 Paul Mollière , Roy van Boekel , Cornelis Petrus Dullemond , Thomas Henning , Christoph Mordasini

We report high-sensitivity millimetre observations of several molecular species (13CO, HCN, HNC, CN, HCO+ and N2H+) in a sample of compact planetary nebulae. Some species such as HCO+ and CN are particularly abundant compared to envelopes…

Astrophysics · Physics 2009-11-07 E. Josselin , R. Bachiller

'Empirical' models (pressure vs. density) of Uranus and Neptune interiors constrained by the gravitational coefficients J_2, J_4, the planetary radii and masses, and Voyager solid-body rotation periods are presented. The empirical…

Earth and Planetary Astrophysics · Physics 2015-05-20 Ravit Helled , John D. Anderson , Morris Podolak , Gerald Schubert

We propose a classification of exoplanet atmospheres based on their H, C, O, N element abundances below about 600 K. Chemical equilibrium models were run for all combinations of H, C, N, O abundances, and three types of solutions were…

Earth and Planetary Astrophysics · Physics 2021-02-10 P. Woitke , O. Herbort , Ch. Helling , E. Stüeken , M. Dominik , P. Barth , D. Samra

Comparatively little is known about atmospheric chemistry on Uranus and Neptune, because remote spectral observations of these cold, distant ``Ice Giants'' are challenging, and each planet has only been visited by a single spacecraft during…

Earth and Planetary Astrophysics · Physics 2021-03-03 J. I. Moses , T. Cavalie , L. N. Fletcher , M. T. Roman

Carbon, nitrogen, and oxygen (CNO) are key elements in stellar formation and evolution, and their abundances should also have a significant impact on planetary formation and evolution. We present a detailed spectroscopic analysis of 74…

Nitrogen oxides are textbook class of molecular compounds, with extensive industrial applications. Nitrogen and oxygen are also among the most abundant elements in the universe. We explore the N-O system at 0 K and up to 500 GPa though ab…

Materials Science · Physics 2015-06-30 Dongxu Li , Artem R. Oganov , Xiao Dong , Xiang-Feng Zhou , Qiang Zhu , Guangrui Qian , Huafeng Dong

It is generally agreed on that the tremendous densities reached in the centers of neutron stars provide a high-pressure environment in which several intriguing particles processes may compete with each other. These range from the generation…

Astrophysics · Physics 2008-11-26 Fridolin Weber , Alexander Ho , Rodrigo P. Negreiros , Philip Rosenfield

The elemental compositions of planet hosting stars serve as proxies for the primordial compositions of the protoplanetary disks within which the planets form. The temperature profile of the disk governs the condensation fronts of various…

Earth and Planetary Astrophysics · Physics 2017-02-01 John M. Brewer , Debra A. Fischer , Nikku Madhusudhan

H2O is an important constituent in planetary bodies, controlling habitability and, in geologically-active bodies, plate tectonics. At pressures within the interior of many planets, the H-bonds in H2O collapse into stronger, ionic bonds.…

The Mg-Si-O system is the major Earth and rocky planet-forming system. Here, through quantum variable-composition evolutionary structure explorations, we have discovered several unexpected stable binary and ternary compounds in the Mg-Si-O…

Geophysics · Physics 2015-10-13 Haiyang Niu , Artem R. Oganov , Xing-Qiu Chen , Dianzhong Li

At high pressure, the typical behavior of elements dictated by the periodic table - including oxidation numbers, stoichiometries in compounds, and reactivity, to name but a few - is altered dramatically. As pressure is applied, the…

Materials Science · Physics 2022-05-11 Katerina P. Hilleke , Tiange Bi , Eva Zurek

Despite the fact that the terrestrial planets formed from the protoplanetary disk, their compositions show marked departures from that of solar nebula condensates. Metallic cores fix oxygen fugacities ($f$O$_2$s) of the planets to 5…

Earth and Planetary Astrophysics · Physics 2025-12-02 Paolo A. Sossi , Remco C. Hin , Thorsten Kleine , Alessandro Morbidelli , Francis Nimmo