Related papers: Hydrogen-helium immiscibility boundary in planets
Analysis of IBEX measurements of neutral interstellar He flux brought the inflow velocity vector different from the results of earlier analysis of observations from GAS/Ulysses. Recapitulation of results on the helium inflow direction from…
Super-Earths and sub-Neptunes are commonly thought to have accreted hydrogen/helium envelopes, consisting of a few to ten percent of their total mass, from the primordial gas disk. Subsequently, hydrodynamic escape driven by core-powered…
Chemical models are routinely used to predict the atmospheric composition of exoplanets and compare it with the composition retrieved from observations, but little is known about the reliability of the calculated composition. We carried out…
Identifying terrestrial planets in the habitable zones (HZs) of other stars is one of the primary goals of ongoing radial velocity and transit exoplanet surveys and proposed future space missions. Most current estimates of the boundaries of…
We have combined the detailed He I recombination model of Smits with the collisional transitions of Sawey & Berrington in order to produce new accurate helium emissivities that include the effects of collisional excitation from both the 2…
We explore the potential multistability of the climate for a planet around the habitable zone. We focus on conditions reminiscent to those of the Earth system, but our investigation aims at presenting a general methodology for dealing with…
We present new narrow-band filter imagery in H-alpha and [N II] 6584 along with UV and optical spectrophotometry measurements from 1200 to 9600 Angstroms of NGC 7293, the Helix Nebula, a nearby, photogenic planetary nebula of large diameter…
The weather layers of the gas giant planets, Jupiter and Saturn, comprise the shallow atmospheric layers that are influenced energetically by a combination of incoming solar radiation and localised latent heating of condensates, as well as…
The observed high covering fractions of neutral hydrogen (HI) with column densities above $\sim 10^{17} \rm{cm}^{-2}$ around Lyman-Break Galaxies (LBGs) and bright quasars at redshifts z ~ 2-3 has been identified as a challenge for…
Understanding the chemical interactions between water and Mg-silicates or iron is essential to constrain the interiors of water-rich planets. Hydration effects have, however, been mostly neglected by the astrophysics community so far. As…
We present results from an atmospheric circulation study of nine hot Jupiters that comprise a large transmission spectral survey using the Hubble and Spitzer Space Telescopes. These observations exhibit a range of spectral behavior over…
The atmospheres of super-Earths and sub-Neptunes can be strongly modified by chemical exchange with their molten interiors during long-lived magma ocean phases. Interpreting atmospheric observations requires fast models that…
Accurate measurements of interstellar deuterium abundances along lines of sight extending out to several hundred parsecs by FUSE and other instruments is making D/H a useful tool for understanding Galactic chemical evolution. We find that…
New techniques, both for generating and detecting turbulence in the helium superfluids 3He-B and 4He, have recently given insight in how turbulence is started, what the dissipation mechanisms are, and how turbulence decays when it appears…
Interior models of Jupiter and Saturn are calculated and compared in the framework of the three-layer assumption, which rely on the perception that both planets consist of three globally homogeneous regions: a dense core, a metallic…
Understanding the planetary envelope composition of sub-Neptune-type exoplanets is challenging due to the inherent degeneracy in their interior composition scenarios. Particularly, the planetary envelope's H2O/H2 ratio, which can also be…
The interior flux of a giant planet impacts atmospheric motion, and the atmosphere dictates the interior's cooling. Here we use a non-hydrostatic general circulation model (Simulating Nonhydrostatic Atmospheres on Planets, SNAP) coupled…
Hot rocky super-Earths are thought to be sufficiently irradiated by their host star to melt their surface and thus allow for long-lasting magma oceans. Some processes have been proposed for such planets to have retained primordial hydrogen…
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,…
Recently, deuterium has been the focus of a high level of experimental and theoretical activity that was sparked by a disagreement on the experimental value of the maximum compression along the Hugoniot. The behavior of deuterium at Mbar…