Dust grain growth and settling in initial gaseous giant protoplanets
نویسندگان
چکیده
Dust grain growth and settling time inside initial gaseous giant protoplanets in the mass range 0.3 to 5 Jovian masses, formed by gravitational instability, have been investigated. We have determined the distribution of thermodynamic and physical variables inside the protoplanets solving the structure equations assuming their gas blobs to be fully convective and with this distribution we have calculated growth and settling time of grains with different initial sizes (10−2 cm ≤ r0 ≤ 1 cm). The results of our calculations are found to be in good agreement with those obtained by different approaches.
منابع مشابه
Rapid Formation of Ice Giant Planets
The existence of Uranus and Neptune presents severe difficulties for the core accretion model for the formation of ice giant planets. We suggest an alternative mechanism, namely disk instability leading to the formation of gas giant protoplanets, coagulation and settling of dust grains to form ice/rock cores at their centers, and photoevaporation of their gaseous envelopes by a nearby OB star, ...
متن کاملCore Formation in Giant Gaseous Protoplanets
Sedimentation rates of silicate grains in gas giant protoplanets formed by disk instability are calculated for protoplanetary masses between 1 MSaturn to 10 MJupiter. Giant protoplanets with masses of 5 MJupiter or larger are found to be too hot for grain sedimentation to form a silicate core. Smaller protoplanets are cold enough to allow grain settling and core formation. Grain sedimentation a...
متن کاملGrain Sedimentation in a Giant Gaseous Protoplanet
We present a calculation of the sedimentation of grains in a giant gaseous protoplanet such as that resulting from a disk instability of the type envisioned by Boss (1998). Boss (1998) has suggested that such protoplanets would form cores through the settling of small grains. We have tested this suggestion by following the sedimentation of small silicate grains as the protoplanet contracts and ...
متن کاملCloud formation in giant planets
We calculate the formation of dust clouds in atmospheres of giant gas-planets. The chemical structure and the evolution of the grain size distribution in the dust cloud layer is discussed based on a consistent treatment of seed formation, growth/evaporation and gravitational settling. Future developments are shortly addressed.
متن کاملPost-Oligarchic Evolution of Protoplanetary Embryos and the Stability of Planetary Systems
In the sequential accretion model, planets form through the sedimentation of dust, cohesive collisions of planetesimals, and coagulation of protoplanetary embryos prior to the onset of efficient gas accretion. As progenitors of terrestrial planets and the cores of gas giant planets, embryos have comparable masses and are separated by the full width of their feeding zones after the oligarchic gr...
متن کامل