Related papers: Coreless Terrestrial Exoplanets
Planets less massive than about 10 MEarth are expected to have no massive H-He atmosphere and a cometary composition (50% rocks, 50% water, by mass) provided they formed beyond the snowline of protoplanetary disks. Due to inward migration,…
From core to atmosphere, the oxidation states of elements in a planet shape its character. Oxygen fugacity (fO$_2$) is one parameter indicating these likely oxidation states. The ongoing search for atmospheres on rocky exoplanets benefits…
The fact that most extrasolar planets found to date are orbiting metal-rich stars lends credence to the core accretion mechanism of gas giant planet formation over its competitor, the disc instability mechanism. However, the core accretion…
Giant planet embryos are believed to be spawned by gravitational instability in massive extended (R ~ 100 AU) protostellar discs. In a recent paper we have shown that dust can sediment inside the embryos, as argued earlier by Boss (1998) in…
We investigate how the statistical distribution of extrasolar planets may be combined with knowledge of the host stars' metallicity to yield constraints on the migration histories of gas giant planets. At any radius, planets that barely…
Large impacts onto young rocky planets may transform their compositions, creating highly reducing conditions at their surfaces and reintroducing highly siderophile metals to their mantles. Key to these processes is the availability of an…
We present a survey of >4,000 star compositions from the Hypatia Catalog to examine whether rocky exoplanets (i.e., those with rocky surfaces, dominated by silicates) might be geologically similar to Earth, at least with respect to…
It has long been known that stars with high metallicity are more likely to host giant planets than stars with low metallicity. Yet the connection between host star metallicity and the properties of small planets is only just beginning to be…
Earth's tectonic processes regulate the formation of continental crust, control its unique deep water and carbon cycles, and are vital to its surface habitability. A major driver of steady-state plate tectonics on Earth is the sinking of…
Some low-density exoplanets are thought to be water-rich worlds that formed beyond the snow line of their protoplanetary disc, possibly accreting coequal portions of rock and water. However, the compositions of bodies within the Solar…
The characterization of Super-Earth-to-Neptune sized exoplanets relies heavily on our understanding of their formation and evolution. In this study, we link a model of planet formation by pebble accretion to the planets' long-term…
In protoplanetary disks, dust grains rich in metallic iron can attract each other magnetically. If they are magnetized to values near saturation, the magnetically induced collision speeds are high enough to knock off the non-magnetized,…
The terrestrial and gas-giant planets in our solar system may represent some prototypes for planets around other stars; the exoplanets because most stars have similar overall elemental abundances as our sun. The solar system planets…
Planets with sizes between those of Earth and Neptune divide into two populations: purely rocky bodies whose atmospheres contribute negligibly to their sizes, and larger gas-enveloped planets possessing voluminous and optically thick…
Nine extrasolar planets with masses between 110 and 430M are known to transit their star. The knowledge of their masses and radii allows an estimate of their composition, but uncertainties on equations of state, opacities and possible…
In the core-accretion model, gas-giant planets form solid cores which then accrete gaseous envelopes. Tidal interactions with disk gas cause a core to undergo inward type-I migration in 10^4 to 10^5 years. Cores must form faster than this…
Magma ocean crystallisation sets up the early structure and long-term evolution of terrestrial planets. Recent seismic evidence signals the presence of a silicate layer at the base of Mars' mantle. Magma-ocean crystallisation and subsequent…
Stars and planets both form by accreting material from a surrounding disk. Because they grow from the same material, theory predicts that there should be a relationship between their compositions. In this study, we search for a…
The core-accretion and disk instability models have so far been used to explain planetary formation. These models have different conditions, such as planet mass, disk mass, and metallicity for formation of gas giants. The core-accretion…
Models of planet formation have shown that giant planets have a large impact on the number, masses and orbits of terrestrial planets that form. In addition, they play an important role in delivering volatiles from material that formed…