\begin{table}%T4
\caption{\label{t:tab3}Distances and ages for globular clusters.}
%\centering
\par
\begin{tabular}{lccc}
\hline\hline
Parameter      &     NGC~6397     &      NGC~6752    &      47~Tuc     \\
\hline
$[$Fe/H$]$     & $-2.03\pm 0.05$ & $-1.43\pm 0.04$ & $-0.66\pm 0.04$ \\
$[\alpha$/Fe$]$& $~0.34\pm 0.02$ & $~0.29\pm 0.02$ & $~0.30\pm 0.02$ \\
$[${\rm M}/H$]$      & $-1.79\pm 0.04$ & $-1.22\pm 0.04$ & $-0.45\pm 0.04$ \\
%\\
$(m-M)_{V(B-V)}$&$12.57\pm 0.03$ & $13.38\pm 0.03$ & $13.47\pm 0.03$ \\
$(m-M)_{V(b-y)}$&$12.62\pm 0.03$ & $13.14\pm 0.03$ & $13.57\pm 0.03$ \\
$<(m-M)_V>$    & $12.60\pm 0.08$ & $13.26\pm 0.08$ & $13.52\pm 0.08$ \\
bin. corrected & $12.58\pm 0.08$ & $13.24\pm 0.08$ & $13.50\pm 0.08$ \\
%\\
$V$(TO)        & $16.56\pm 0.02$ & $17.39\pm 0.03$ & $17.68\pm 0.05$ \\
$V$(HB)        & $13.11\pm 0.10$ & $13.84\pm 0.10$ & $14.13\pm 0.10$ \\
$M_V$(TO)      &  $3.98\pm 0.08$ &  $4.15\pm 0.08$ &  $4.18\pm 0.08$ \\
$M_V$(HB)      &  $0.53\pm 0.13$ &  $0.60\pm 0.13$ &  $0.63\pm 0.13$ \\
%\\
Age (no diff.)~(Gyr) &  $13.9\pm 1.1$  &  $13.8\pm 1.1$ &   $11.2\pm 1.1$  \\
Age (diff.)~(Gyr)    &  $13.5\pm 1.1$  &  $13.4\pm 1.1$ &   $10.8\pm 1.1$  \\
\hline
\end{tabular}
\end{table}