\begin{table}%t1
%%\centering
\par
\caption{Differential astrometry for HE~0047$-$1756, based on the GALFIT results for
the $i$ and $K_{\rm s}$ band images.
Component A is the brighter of the two~QSO components. The quoted error bars 
are only the internal errors given by the fitting routine.
The last object is the faint blob southwest of component~B.
\label{tab:pos}}
$$
\begin{tabular}{lr@{$\;\pm\;$}lr@{$\;\pm\;$}l}
%{l.@{\mbox{\hspace{0.5em}$\pm$}\hspace{-1.25em}}.@{\hspace{-1em}}.@{\mbox{\hspace{-2.0em}$\pm$}\hspace{-1.25em}}.}
\hline\hline\noalign{\smallskip}
Component/band & \multicolumn{2}{c}{$\Delta\alpha$} & \multicolumn{2}{c}{$\Delta\delta$} \\
          & \multicolumn{2}{c}{[arcsec]} & \multicolumn{2}{c}{[arcsec]} \\
\noalign{\smallskip}\hline\noalign{\smallskip}
A         &  0.000   & 0.000  &    0.000 & 0.000 \\[0.5ex]
B ($i$)   &  0.226   & 0.001  &    $-$1.418  & 0.001 \\  
B ($K_{\rm s}$) &  0.230   & 0.001  &    $-$1.433 & 0.001 \\[0.5ex]
G ($i$)   &  0.227   & 0.007  &    $-$0.865 & 0.013 \\
G ($K_{\rm s}$) &  0.267   & 0.008  &    $-$0.881 & 0.009 \\[0.5ex]
blob      &$-$0.07 & 0.15   & $-$2.36  & 0.15 \\
\noalign{\smallskip}\hline
\end{tabular}
$$
\end{table}