\begin{table}%t3
\caption{\label{tab_pm1}Common proper motions with Hipparcos stars in mas/yr.}
%\centering
\par
\begin{tabular}{l c c c}
\hline\hline\noalign{\smallskip}
Object & $\mu_{\alpha}\cos{\delta}$ & $\mu_{\delta}$ & $\varepsilon$ \\
\hline
Hip~63510A & $-$616.3 $\pm$ 1.5 &  $-$13.6 $\pm$ 1.0 & \\
ULAS~J1300$+$12  & $-$596 $\pm$ 7 &   $+$1 $\pm$ 7 & 23\\
\hline
Hip~73786A & $-$608.8 $\pm$ 2.7 & $-$502.7 $\pm$ 3.6 & \\
ULAS~J1504$+$05  & $-$614 $\pm$ 4 & $-$496 $\pm$ 8 & 22\\
\hline
\end{tabular}
\tablefoot{Proper motions from linear fitting of the positions
given in Table~\ref{tab_astm1}. For Hipparcos primaries
data are taken from van Leeuwen (\cite{vanleeuwen07}).
$\varepsilon$ are the expected errors (see text).}%\vspace*{-1mm}
\end{table}