Abstract
In this paper, the distribution of thermodynamic variables in the protoplanets formed by gravitational instability in the mass range 0.3 - 10 MJ ( 1 MJ = 1 Jupiter mass = 1.8986 × 1030 gm) is investigated in their initial state by solving the structure equations via the Adomian decomposition method. Concerning the heat transfer in the protoplanets, the mode of convection is taken into account. The outcomes indicate that there is a reasonably good agreement between the Adomian semi-analytical solution containing only first 8 terms and the numerical results.