\begin{table}%t4
%\centering
\par
\caption{\label{tabages}Mean ages and standard age deviations (in Myr) for the various samples of PMS candidates in NGC~6383.}
\begin{tabular}{l c c c c}
\hline\hline\noalign{\smallskip}
& \multicolumn{2}{c}{X-ray selected} & \multicolumn{2}{c}{PNZ objects} \\
& mean & stand.\ dev. & mean & stand.\ dev. \\
\hline\noalign{\smallskip}
DM97       & 1.9 & 2.5 & 2.6 & 4.0 \\
SDF00      & 3.8 & 3.0 & 2.8 & 2.9 \\
LMV09 std. & 2.1 & 2.6 & 1.9 & 2.9 \\
LMV09 rot. & 1.7 & 2.3 & 1.8 & 3.0 \\
\hline
\end{tabular}
\end{table}