\begin{table}%t1
%\centering
\par
\caption{Slopes of the linear fits to the logarithm of the mean weighted PWTs without any
correction for the magnitude of
the stars. }
%\begin{center}
\par
\begin{tabular}{c c c} \hline \hline\noalign{\smallskip}
 Spectral & Slope from $1.0\times 10^{-4}$ & Slope from $0.7\times 10^{-3}$ \\
 type & to $0.6\times 10^{-3}$ Hz  & to $2.5\times 10^{-3}$ Hz \\ \hline
 F &  $-0.600  \pm 0.019 $ &   $ -0.502\pm 0.006$\\
 G &  $-0.513  \pm 0.015 $ &   $ -0.351\pm 0.006$\\
 K &  $-0.656  \pm 0.019 $ &   $ -0.579\pm 0.011$ \\
 M &  $-0.724  \pm 0.016 $ &   $ -0.567\pm 0.013$\\ \hline
\par
\end{tabular}
%\end{center}
\par
\end{table}