\begin{table}%t3
%\centering
\par
\caption{\label{OrbPar_2M0310}Orbital parameters for the 2MASS0310+1648~AB system.}
\begin{tabular}{l l c c }    
\hline\hline
\noalign{\medskip}
& & HST/NIC1 &VLT/NACO\\
\raisebox{1.5ex}[1.5ex]{Parameter} & & (24/09/2004) & (05/11/2007)\\
\hline
\noalign{\smallskip}
Separation & $\rho$ [mas] &  204.3 $\pm$ 0.4 & 210.8 $\pm$ 1.8 \\[0.5ex]
Position Angle & $\theta$ [deg]   &  206.4 $\pm$ 0.1 &  221.9 $\pm$ 0.8 \\[1ex]
estimated distance & $d$ [pc] &  \multicolumn{2}{c}{25 $\pm$ 4}\\ [0.5ex]
Semi-major axis & $a$ [AU]   & \multicolumn{2}{c}{\hspace{-2.5ex}$\ge$5.2 $\pm$ 0.8}\\ [0.5ex]
Orbital period & $P$ [years]   & \multicolumn{2}{c}{72 $\pm$ 4}\\[0.5ex]
System mass & $M_{\rm tot}$ [$M_{\rm Jup}$]  & \multicolumn{2}{c}{\hspace{-1.5ex}$\ge$30}\\ 
\noalign{\smallskip}
\hline
\end{tabular}
\end{table}