相关论文: Formation of planets by tidal downsizing of giant …

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…

According to the sequential accretion model, giant planet formation is based first on the formation of a solid core which, when massive enough, can gravitationally bind gas from the nebula to form the envelope. In order to trigger the…

Terrestrial planets form in a series of dynamical steps from the solid component of circumstellar disks. First, km-sized planetesimals form likely via a combination of sticky collisions, turbulent concentration of solids, and gravitational…

Planet formation encompasses processes that span a remarkable 40 magnitudes in mass, ranging from collisions between micron-sized grains inherited from the ISM to the accretion of gas by giant planets. The planet formation process takes…

It has been proposed recently that the first step in the formation of both rocky and gas giant planets is dust sedimentation into a solid core inside a gas clump (giant planet embryo). The clumps are then assumed to migrate closer to the…

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…

Massive cores of the giant planets are thought to have formed in a gas disk by accretion of pebble-size particles whose accretional cross-section is enhanced by aerodynamic gas drag [1][2]. A commonly held view is that the terrestrial…

I discuss the role that disc fragmentation plays in the formation of gas giant and terrestrial planets, and how this relates to the formation of brown dwarfs and low-mass stars, and ultimately to the process of star formation. Protostellar…

The standard picture of planet formation posits that giant gas planets are over-grown rocky planets massive enough to attract enormous gas atmospheres. It has been shown recently that the opposite point of view is physically plausible: the…

It is widely held that the first step in forming the gas giant planets, such as Jupiter and Saturn, is to form solid `cores' of roughly 10 M$_\oplus$. Getting the cores to form before the solar nebula dissipates ($\sim\!1-10\,$Myr) has been…

We review the current theoretical understanding how growth from micro-meter sized dust to massive giant planets occurs in disks around young stars. After introducing a number of observational constraints from the solar system, from observed…

Gas-giant planets, such as Jupiter, Saturn and massive exoplanets, were formed via the gas accretion onto the solid cores each with a mass of roughly ten Earth masses. However, rapid radial migration due to disk-planet interaction prevents…

The standard model for planet formation is a bottom-up process in which the origin of rocky and gaseous planets can be traced back to the collision of micron-sized dust grains within the gas-rich environment of protoplanetary disks. Key…

Core Accretion, the most widely accepted scenario for planet formation, postulates existence of km-sized solid bodies, called planetesimals, arranged in a razor-thin disc in the earliest phases of planet formation. In the Tidal Downsizing…

Our understanding of the process of terrestrial planet formation has grown markedly over the past 20 years, yet key questions remain. This review begins by first addressing the critical, earliest stage of dust coagulation and concentration.…

Motivated by the recent discovery of massive planets on wide orbits, we present a mechanism for the formation of such planets via disk fragmentation in the embedded phase of star formation. In this phase, the forming disk intensively…

Planet formation is directly linked to the birthing environment that protoplanetary disks provide. The disk properties determine whether a giant planet will form and how it evolves. The number of exoplanet and disk observations is…

Planetary systems are born in the disks of gas, dust and rocky fragments that surround newly formed stars. Solid content assembles into ever-larger rocky fragments that eventually become planetary embryos. These then continue their growth…

In models of planetary accretion, pebbles form by dust coagulation and rapidly migrate toward the central star. Planetesimals may continuously form from pebbles over the age of the protoplanetary disk by yet uncertain mechanisms. Meanwhile,…

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…