A R T I C L E I N F O

Article history :

Received 26 August 2013

Revised 27 June 2014

Accepted 27 June 2014

Available online 10 July 2014

Keywords :

Accretion

Jovian planets

Jupiter

Planetary formation

Planetesimals

Article in press .
This is an unofficial preprint prepared by the authors from the accepted manuscript .

A B S T R A C T

We present calculations of the early stages of the formation of Jupiter via core nucleated accretion and gas capture .
The core begins as a seed body of about 350 kilometers in radius and orbits in a swarm of planetesimals whose initial radii range from 15 meters to 50 kilometers .
The evolution of the swarm accounts for growth and fragmentation , viscous and gravitational stirring , and for drag-assisted migration and velocity damping .
During this evolution , less than 9 % of the mass is in planetesimals smaller than 1 kilometer in radius ; \lesssim 25 % is in planetesimals with radii between 1 and 10 kilometers ; and \lesssim 7 % is in bodies with radii larger than 100 kilometers .
Gas capture by the core substantially enhances the size-dependent cross-section of the planet for accretion of planetesimals .
The calculation of dust opacity in the planet ’ s envelope accounts for coagulation and sedimentation of dust particles released as planetesimals are ablated .
The calculation is carried out at an orbital semi-major axis of 5.2 \mathrm { AU } and the initial solids ’ surface density is 10 \mathrm { g cm ^ { -2 } } at that distance .
The results give a core mass of nearly 7.3 Earth masses ( \mathrm { M } _ { \oplus } ) and an envelope mass of \approx 0.15 \mathrm { M } _ { \oplus } after about 4 \times 10 ^ { 5 } years , at which point the envelope growth rate surpasses that of the core .
The same calculation without the envelope yields a core of only about 4.4 \mathrm { M } _ { \oplus } .

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