Related papers: Exoplanetary Interiors
In the last 15 years, since the discovery of the first low-mass planets beyond the solar system, there has been tremendous progress in understanding the diversity of (super-)Earth and sub-Neptune exoplanets. Especially the influence of the…
Since the discovery of the first extrasolar planet more than twenty years ago, we have discovered nearly four thousand planets orbiting stars other than the Sun. Current observational instruments (on board the Hubble Space Telescope,…
The anomalously large radii of strongly irradiated exoplanets have remained a major puzzle in astronomy. Based on a 2D steady state atmospheric circulation model, the validity of which is assessed by comparison to 3D calculations, we reveal…
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…
Knowledge of both the mass and radius of an exoplanet allows us to estimate its mean density, and therefore its composition. Exoplanets seem to fill a very large parameter space in terms of mass and composition, and unlike the…
Exoplanets host stars present a clear metallicity excess compared to stars without detected planets, with an average overabundance of 0.2 dex. This excess may be primordial, in which case the stars should be overmetallic down to their…
The number of extrasolar planets discovered is increasing, so that more than five thousand exoplanets have been confirmed to date. Now we have an opportunity to test the validity of the laws governing planetary systems and take steps to…
Mercury's core mass fraction (CMF) is ~0.7, more than double that of the other rocky planets in the solar system, which have CMFs of ~0.3. The origin of Mercury's large, iron-rich core remains unknown. Adding to this mystery, an elusive…
Some exoplanets have much higher densities than expected from stellar abundances of planet-forming elements. There are two theories - metal-rich formation hypothesis and naked core hypothesis - that explain how formation and evolution can…
In the last decade, about a dozen giant exoplanets have been directly imaged in the IR as companions to young stars. With photometry and spectroscopy of these planets in hand from new extreme coronagraphic instruments such as SPHERE at VLT…
Massive and water-rich planets should be ubiquitous in the universe. Many of those worlds are expected to be subject to important irradiation from their host star, and display supercritical water layers surrounded by extended steam…
Small planets ($\sim$1--3.9 $\Rearth$) constitute more than half of the inventory of the 4000-plus exoplanets discovered so far. Smaller planets are sufficiently dense to be rocky, but those with radii larger than $\sim$1.6 $\Rearth$ are…
Because of their common origin, it was assumed that the composition of planet building blocks should, to a first order, correlate with stellar atmospheric composition, especially for refractory elements. In fact, information on the relative…
This review is focused on describing the logic by which we make predictions of exoplanetary compositions and mineralogies, and how these processes could lead to compositional diversity among rocky exoplanets. We use these predictions to…
The ever-expanding catalog of detected super-Earths calls for theoretical studies of their properties in the case of a substantial water layer. This work considers such water planets with a range of masses and water mass fractions (2 to 5…
Exoplanets around different types of stars provide a window into the diverse environments in which planets form. This chapter describes the observed relations between exoplanet populations and stellar properties and how they connect to…
Mass and radius are two fundamental properties for characterising exoplanets, but only for a relatively small fraction of exoplanets are they both available. Mass is often derived from radial velocity measurements, while the radius is…
Planets with sizes between that of Earth (with radius R$_\oplus$) and Neptune (about 4 R$_\oplus$) are now known to be common around Sun-like stars. Most such planets have been discovered through the transit technique, by which the planet's…
Rocky planet compositions regulate planetary evolution by affecting core sizes, mantle properties, and melting behaviours. Yet, quantitative treatments of this aspect of exoplanet studies remain generally under-explored. We attempt to…
Most detected transiting planets have orbits which would fit within the one of Mercury, exposing them to intense stellar irradiation and interactions that significantly alter their properties. In contrast, colder planets with longer orbital…