Related papers: Interior structure models of GJ 436b
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 a detailed analysis of the dayside atmosphere of the hot-Neptune GJ~436b, based on recent Spitzer observations. We report statistical constraints on the thermal and chemical properties of the planetary atmosphere, study…
Transmission spectroscopy is enabling precise measurements of atmospheric H2O abundances for numerous giant exoplanets. For hot Jupiters, relating H2O abundances to metallicities provides a powerful probe of their formation conditions.…
GJ 436b is a prime target for understanding warm Neptune exoplanet atmospheres and a target for multiple JWST GTO programs. Here, we report the first space-based optical transmission spectrum of the planet using two HST/STIS transit…
This article provides an overview of how models of giant planet interiors are constructed. We review measurements from past space missions that provide constraints for the interior structure of Jupiter. We discuss typical three-layer…
Temperate exoplanets between the sizes of Earth and Neptune, known as "sub-Neptunes", have emerged as intriguing targets for astrobiology. It is unknown whether these planets resemble Earth-like terrestrial worlds with a habitable surface,…
GJ 436b is the archetype warm Neptune exoplanet. The planet's thermal emission spectrum was previously observed via intensive secondary eclipse campaigns with Spitzer. The atmosphere has long been interpreted to be extremely metal-rich, out…
We present a 3D fully selfconsistent multi-fluid hydrodynamic aeronomy model to study the structure of a hydrogen dominated expanding upper atmosphere around the hot Jupiter HD 209458b and the warm Neptune GJ 436b. In comparison to previous…
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…
We developed a 1D photo-thermochemical model to study the atmosphere of warm exoplanets. The chemical scheme used in this model is completely new in planetology and has been constructed in collaboration with specialists of combustion. It…
Observations of transmission spectra reveal that hot Jupiters and Neptunes are likely to possess escaping atmospheres driven by stellar radiation. Numerous models predict that magnetic fields may exert significant influences on the…
Kepler has found hundreds of Neptune-size (2-6 R_Earth) planet candidates within 0.5 AU of their stars. The nature of the vast majority of these planets is not known because their masses have not been measured. Using theoretical models of…
In order to accurately model giant planets, a whole set of observational constraints is needed. As the conventional constraints for extrasolar planets like mass, radius, and temperature allow for a large number of acceptable models, a new…
The sample of known exoplanets is strongly biased to masses larger than the ones of the giant gaseous planets of the solar system. Recently, the discovery of two extrasolar planets of considerably lower masses around the nearby stars GJ 436…
We report precise Doppler measurements of GJ 436 (M2.5V) obtained at Keck Observatory. The velocities reveal a planetary companion with orbital period of 2.644 d, eccentricity of 0.12 (consistent with zero) and velocity semi-amplitude of $K…
The increasing precision of planetary mass and radius observations is bringing major questions about the structure and formation of planets--such as the nature of the radius valley and origin of super-Mercuries--within reach, demanding the…
Many planets in the solar system and across the galaxy have hydrogen-rich atmospheres overlying more heavy element-rich interiors with which they interact for billions of years. Atmosphere-interior interactions are thus crucial to…
The late-type dwarf GJ 436 is known to host a transiting Neptune-mass planet in a 2.6-day orbit. We present results of our interferometric measurements to directly determine the stellar diameter ($R_{\star} = 0.455 \pm 0.018 R_{\odot}$) and…
Exoplanets with masses between Earth and Neptune are amongst the most commonly observed, yet their properties are poorly constrained. Their transmission spectra are often featureless, which indicate either high-altitude clouds or a high…
The recent JWST detections of carbon-bearing molecules in a habitable-zone sub-Neptune have opened a new era in the study of low-mass exoplanets. The sub-Neptune regime spans a wide diversity of planetary interiors and atmospheres not…