相关论文: Compositions and origins of outer planet systems: …
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…
Among exoplanets, the small-size population constitutes the dominant one, with a diversity of properties and compositions ranging from rocky to gas dominated envelope. While a large fraction of them have masses and radii similar to or…
The planets of our solar system formed from a gas-dust disk. However, there are some properties of the solar system that are peculiar in this context. First, the cumulative mass of all objects beyond Neptune (TNOs) is only a fraction of…
Condensed planets contract or expand as their temperature changes. With the exception of the effect of phase changes, this phenomenon is generally interpreted as being solely related to the thermal expansivity of the planet's components.…
Studies of transiting extra-solar planets are of key importance for understanding the nature of planets outside our Solar System, because their densities can be determined, constraining of what the planets are made of. Using the data…
Exoplanets smaller than Neptune are common around red dwarf stars (M dwarfs), with those that transit their host star constituting the bulk of known temperate worlds amenable for atmospheric characterization. We analyze the masses and radii…
The core accretion theory of planet formation has at least two fundamental problems explaining the origins of Uranus and Neptune: (1) dynamical times in the trans-Saturnian solar nebula are so long that core growth can take > 15 Myr, and…
Sub-Saturns straddle the boundary between gas-rich Jupiters and gas-poor super-Earths/sub-Neptunes. Their large radii (4--8$R_\oplus$) suggest that their gas-to-core mass ratios range $\sim$0.1--1.0. With their envelopes as massive as their…
A considerable amount of information regarding the processes that occurred during the accretion of the early planetesimals is still present among the small bodies of our solar system. A review of our current knowledge of the density of…
Hot Jupiters formed through circularization of high-eccentricity orbits should be found at orbital separations $a$ exceeding $twice$ that of their Roche limit $a_{\rm R}$. Nevertheless, about a dozen giant planets have now been found well…
The recent discovery of dense rings around the Centaur Chariklo (and possibly Chiron) reveals that complete dense planetary rings are not only found around Saturn and Uranus, but also around small bodies orbiting in the vicinity of those…
Exoplanetary systems that contain multiple planets on short-period orbits appear to be prevalent in the current observed exoplanetary population, yet the processes that give rise to such configurations remain poorly understood. A common…
The Kepler-36 system consists of two planets that are spaced unusually close together, near the 7:6 mean motion resonance. While it is known that mean motion resonances can easily form by convergent migration, Kepler-36 is an extreme case…
We investigate orbital resonances expected to arise when a system of two planets, with masses in the range 1-4 Earth masses, undergoes convergent migration while embedded in a section of gaseous disc where the flow is laminar. We consider…
The central density rho_0 of a stellar cluster is an important physical parameter for determining its evolutionary and dynamical state. How much mass segregation there is, or whether the cluster has undergone core collapse both depends on…
Context. The orbital distribution of exoplanets indicates an accumulation of super-Earth sized planets close to their host stars in compact systems. When an inward disc-driven migration scenario is assumed for their formation, these planets…
The rotational distribution of asteroids as a function of their size is used {as a diagnostic of} their physical properties and evolution. Recent photometric surveys from the Gaia mission, allowing observation of asteroids with long spin…
In co-orbital planetary systems, two or more planets share the same orbit around their star. Here we test the dynamical stability of co-orbital rings of planets perturbed by outside forces. We test two setups: i) 'stationary' rings of…
Ice-rich planets are formed exterior to the water ice-line and thus are expected to contain a substantial amount of ices. The high ice content leads to unique conditions in the interior, under which the structure of a planet is affected by…
Planets and the stars they orbit are born from the same cloud of gas and dust, and the primordial compositions of rocky exoplanets have been assumed to have iron and refractory abundance ratios consistent with their host star. To test this…