\begin{table}%T6
\caption{\label{tab:col6}List of iron core candidate stars selected from the data by 
Provencal et~al. (\cite{Provencal1998}). Procyon~B has been excluded already from their data.}
%\centering
\par
\begin{tabular}{clllcr}
    \hline\hline
WD &  $M/M_{\odot}$ & $\log g$ & $R/R_{\odot}$ & $U-B$ & $B-V$ \\
\hline  
EG 21       & 0.554 & 8.06 & 0.0115  &  $-$0.55 &  0.05  \\
EG~50       & 0.497 & 8.10 & 0.0104  &  $-$0.91 & $-$0.08  \\
G 238-44    & 0.417 & 7.90 & 0.0120  &  $-$0.86 & $-$0.09  \\
G 181-B55   & 0.50  & 8.05 & 0.0110  &  $-$0.55 &  0.17  \\
GD~140      & 0.797 & 8.48 & 0.0085  &  $-$0.95 & $-$0.06  \\
GD 279      & 0.411 & 7.83 & 0.0129  &  $-$0.60 &  0.10  \\ 
WD 2007-303 & 0.433 & 7.86 & 0.0128  &  $-$0.66 &  0.07  \\
\hline
\end{tabular}
%\vspace*{-2mm}
\end{table}