\begin{table}%T3
%\centering
\par
\caption
{Effective temperatures, surface gravities, and masses of the halo white
  dwarfs. \label{ha_par}}
\begin{tabular}{llll}
\hline
\hline
star & $T_{\rm eff}$ & ${\rm log}~g$ & $M$ \\ 
   &${\rm K}$ & ${\rm cm ~s^{-2}} $  & \Msolar \\
\hline
 HS1527+0614 & 14015 &  7.80 &  0.50 \\
  WD1448+077 & 14459 &  7.66 &  0.44 \\
  WD2351$-$368 & 14567 &  7.81 &  0.51 \\
  WD0252$-$350 & 17056 &  7.42 &  0.35 \\
  WD2359$-$324 & 23267 &  7.65 &  0.47 \\
  WD1524$-$749 & 23414 &  7.61 &  0.45 \\
 HE0201$-$0513 & 24604 &  7.67 &  0.48 \\
\hline
\end{tabular}
\end{table}