\begin{table}%t3
   \caption{Relative position and velocities of the components of HD~219542
              in the cartesian plane.}
     \label{t:posvel}
%\centering
\par
       \begin{tabular}{ccc}
         \hline
         \hline
         Parameter      &  Value & Error  \\
         \hline
$x$ (AU)       &  246  &  26  \\
$y$ (AU)       &  151  &  16  \\
$z_{{\rm min}}$ (AU) &$-$1260  & 280  \\
$z_{{\rm max}}$ (AU) & 1260  & 280  \\
$v_{x}$ (m s$^{-1}$)  &  840  & 140  \\
$v_{y}$ (m s$^{-1}$)  & 1020  & 110  \\
$v_{z}$ (m s$^{-1}$)  &$-$1150  &  25  \\
         \hline
      \end{tabular}
\end{table}