\begin{table}%t1
\caption{\label{tab:crawffstars}Comparison between absolute magnitude calibrations for different mean values of $\overline{\beta}$.}
%\centerline
{\begin{tabular}{rrrr}
\hline\hline\noalign{\smallskip}
$\overline{\beta}$ & ${\overline{M_{\rm c}}}(\varpi)$ &  ${\overline{M_{\rm c}}({\rm cor})}$ & ${\overline{M_{\rm c}}(HIP)}$ \\
\hline
2.604 & $4.77\pm0.23$ & $4.64\pm0.22$ & $4.677\pm0.044$ \\
2.631 & $4.21\pm0.25$ & $4.03\pm0.26$ & $4.115\pm0.038$ \\
2.648 & $3.92\pm0.30$ & $3.69\pm0.30$ & $3.830\pm0.043$ \\
2.671 & $3.69\pm0.52$ & $3.43\pm0.58$ & $3.529\pm0.050$ \\
2.711 & $3.53\pm0.12$ & $3.33\pm0.17$ & $3.237\pm0.087$ \\
\hline
\end{tabular}}
\medskip
 The first three columns are from \citet{crawford75}; the final column from the current paper, using the least squares solution that provided the coefficient in Eq.~(\ref{equ:mv_calibr_clust}).
\end{table}