\begin{table}%t17
\caption{\label{table:relazioniPLlineari-OS}Theoretical $PL$ relations for fundamental noncanonical pulsators (see text).
}      
%\centering
\par
\begin{tabular}{l l l l}
  \hline\hline
Case & $a$ & $b$ & $\sigma$ \\
  \hline
         &      &$\overline{M_V}$&\\
 $ncOS$ & --1.60$ \pm $0.04 & --2.34$ \pm $0.03 & 0.29 \\
  $ncOS$ $cut$ & --1.47$ \pm $0.04 & --2.47$ \pm $0.04 & 0.28 \\
             &  &$\overline{M_I}$&\\
$ncOS$ & --2.01$ \pm $0.03 & --2.7$ \pm $0.02 & 0.21 \\
  $ncOS$ $cut$ & --1.92$ \pm $0.03 & --2.8$ \pm $0.03 & 0.20 \\
             &  &$\overline{M_K}$&\\
$ncOS$ & --2.43$ \pm $0.01 & --3.21$ \pm $0.01 & 0.08 \\
  $ncOS$ $cut$ & --2.39$ \pm $0.01 & --3.25$ \pm $0.01 & 0.08 \\
\hline
\end{tabular}
\end{table}