\begin{table}%t4
\caption{Position and velocity of LSR, and local density (Kerr \& 
         Lynden-Bell \cite{Kerr86}), bulge, disk and halo parameters 
         (Miyamoto \& Nagai \cite{Miyamoto75}; Allen \& Santill\'an 
         \cite{Allen91}), together with spiral structure (Fern\'andez et~al.
         \cite{Fernandez01}) and central bar (Binney et~al. 
         \cite{Binney91}; Palou\u s et~al. \cite{Palous93}) parameters 
         used in the integration of stellar orbits.}
\label{tab.parorb}
%\centering
\par
\begin{tabular}{ll}
        \hline\hline
$R_{\odot}$            &  8.5 kpc \\
$\Theta_{\odot}$       & 220 km s$^{-1}$ \\
$\rho_{\odot}$         &  0.15  $M_{\odot}$~~pc$^{-3}$   \\
        \hline\noalign{\smallskip}
$M_{\rm B}$        &  $1.4\times 10^{10}$ $M_{\odot}$ \\
$M_{\rm D}$        &  $8.6\times 10^{10}$ $M_{\odot}$ \\
$M_{\rm H}$        &  $1.1\times 10^{11}$ $M_{\odot}$ \\
$a_{\rm B}$        &  0.39 kpc \\
$a_{\rm D}$        &  5.3  kpc \\
$b_{\rm D}$        &  0.25 kpc \\
$a_{\rm H}$        & 12.0  kpc \\
        \hline\noalign{\smallskip}
$m$                   &     2       \\
$i$                   &   $-6\degr$ \\
$\psi_{\odot}$         &  330$\degr$ \\
$f_{{\rm r}}$      &    0.05     \\
$\Omega_{{\rm p}}$ & 30 km s$^{-1}$ kpc$^{-1}$ \\
\hline
${a_{\rm B}}/{b_{\rm B}}$ \hspace{0.5cm} &    2.381    \\
${a_{\rm B}}/{c_{\rm B}}$ &    3.030    \\
$q_{\rm B}$        &     5 kpc   \\
$t_o$                 &    $5 \times 10^8$ years \\
$\theta_o$            & 45\degr     \\
$\Omega_{\rm B}$   & 70 km s$^{-1}$ kpc$^{-1}$ \\
\hline
\end{tabular}
\end{table}