相关论文: Small Planetesimals in a Massive Disk Formed Mars
Recent observations of protoplanetary disks have revealed ring-like structures that can be associated to pressure maxima. Pressure maxima are known to be dust collectors and planet migration traps. Most of planet formation works are based…
The cores of wide-orbit giant planets can form via pebble accretion if large planetesimals form in the outer regions of protoplanetary discs at sufficiently early times. Streaming instability simulations support mass distributions…
We hypothesise that planets are made by tidal downsizing of migrating giant planet embryos. The proposed scheme for planet formation consists of these steps: (i) a massive young protoplanetary disc fragments at R ~ several tens to hundreds…
We propose a pebble-driven core accretion scenario to explain the formation of giant planets around the late-M dwarfs of $M_{\star}{=}0.1{-}0.2 \ M_{\odot}$. In order to explore the optimal disk conditions for giant planet, we perform…
If planetesimal formation is an efficient process, as suggested by several models involving gravitational collapse of pebble clouds, then, before long, a significant part of the primordial dust mass should be absorbed in many km sized…
Terrestrial planets are believed to be formed via giant impacts of Mars-sized protoplanets. Planets formed via giant impacts have highly eccentric orbits. A swarm of planetesimals around the planets may lead to eccentricity damping for the…
Estimates of the frequency of planetary systems in the Milky Way are observationally limited by the low-mass planet regime. Nevertheless, substantial evidence for systems with undetectably low planetary masses now exist in the form of…
The formation of planets depends on the underlying protoplanetary disc structure, which influences both the accretion and migration rates of embedded planets. The disc itself evolves on time-scales of several Myr during which both…
The formation of giant planets requires accumulation of ~10 Earth mass in solids; but how do protoplanets acquire their mass? There are many, often competing processes that regulate the accretion rate of protoplanets. To assess their…
Smaller terrestrial planets (< 0.3 Earth masses) are less likely to retain the substantial atmospheres and ongoing tectonic activity probably required to support life. A key element in determining if sufficiently massive "sustainably…
This paper presents a new terrestrial planet formation theory demonstrating that Earth-mass planets form naturally in tandem protosolar disks. Our model builds upon tandem planet formation theory (Ebisuzaki and Imaeda 2017; Imaeda and…
Planet formation around one component of a tight, eccentric binary system such as $\gamma$ Cephei (with semimajor axis around 20 AU) is theoretically challenging because of destructive high-velocity collisions between planetesimals. Despite…
Almost all the planets of our solar system have moons. Each planetary system has however unique characteristics. The Martian system has not one single big moon like the Earth, not tens of moons of various sizes like for the giant planets,…
The formation of planets is one of the major unsolved problems in modern astrophysics. Planets are believed to form out of the material in circumstellar disks known to exist around young stars, and which are a by-product of the star…
In the standard model of core accretion, the formation of giant planets occurs by two main processes: first, a massive core is formed by the accretion of solid material; then, when this core exceeds a critical value (typically greater than…
Planets grow via the collisional accretion of small bodies in a protoplanetary disk. Such small bodies feel strong gas drag and their orbits are significantly affected by the gas flow and atmospheric structure around the planet. We…
How big were the first planetesimals? We attempt to answer this question by conducting coagulation simulations in which the planetesimals grow by mutual collisions and form larger bodies and planetary embryos. The size frequency…
The process of gravitational scattering of planetesimals by a massive protoplanetary embryo is explored theoretically. We propose a method to describe the evolution of the disk surface density, eccentricity, and inclination caused by the…
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…
The timing of formation for the first planetesimals determines the mode of planetary accretion and their geophysical and compositional evolution. Astronomical observations of circumstellar discs and Solar System geochronology provide…