  Using the Relativistic Mean Field Theory (RMF) it is shown that different
proton fraction which is directly connected with the neutron excess and with
the asymmetry of the system affects proto-neutron stars parameters and changes
their composition. The obtained form of the equation of state allows to
construct the mass-radius relations and shows that the increasing asymmetry
creates more compact stars. The inclusion of delta meson together with
nonlinear vector meson interaction terms and magnetic field make this effect
even stronger.
