\begin{table}%t1
      \caption{Symbols.         \label{TabSymbol}}
     $$
         \begin{tabular}{ll}
            \hline\hline
            \noalign{\smallskip}
            $\rm Symbol^{\dagger}$                                    &  Meaning  \\
            \noalign{\smallskip}
            \hline
            \noalign{\smallskip}
            $a$ [AU]                                                    & orbital distance  \\
            $G=6.67259 \times 10^{-11}$                                        & gravitational constant\\
            $\mu=2.3 \times 10^{-3}$                                             & mean molecular weight \\
            $M_{{\rm core}}$                                        & predefined core mass     \\
            $M_{{\rm env}}$                                         & envelope mass     \\
            $M_{{\rm tot}}$                                         & total mass \\
            $M(r)$                                                      & total mass interior to radius \textit{r}\\
            $M_{\odot}=1.989 \times 10^{30}$                                   & solar mass\\
            $M_{\oplus}=5.976 \times 10^{24}$                                  & Earth mass\\
            $r_{{\rm core}}$                                        & core radius \\
            $r_{{\rm Hill}}$                                        & Hill sphere radius \\
            $\Re=8.31441 $                                              & molar gas constant\\
            $\varrho_{{\rm core}}=5500 $                            & predefined core density \\
            $\varrho_{{\rm csg}}$                                   & envelope gas density at core surface\\
            $\varrho_{{\rm env}}$                                   & envelope gas density  \\
            $T(a)$                                                      & nebula gas temperature\\
            \noalign{\smallskip}
            \hline
         \end{tabular}
     $$
             $^{{\rm \dagger}}$  SI units used unless otherwise specified.
        \end{table}