\begin{table}
\begin{footnotesize}
\caption[]{\label{cham_table3} Stars with discordant proper motions in one or
more catalogues. As usual, all proper motions have been transformed to the astrometric
reference system defined by Hipparcos, so no systematic differences should be
present.}
\bigskip
\begin{minipage}{8cm}
\begin{center}
\begin{tabular}{lr@{}lr@{}lll}
\noalign{\smallskip}
\hline\noalign{\smallskip}
[mas/a] & 
\multicolumn{2}{c}{$\mu_{\alpha}$} &
\multicolumn{2}{c}{$\mu_{\delta}$} & 
\multicolumn{1}{c}{\raisebox{1ex}[-1ex]{$\sigma_{\mu_{\alpha}}$}
\raisebox{-1ex}[1ex]{\scriptsize \hspace*{-0.7cm}$\cos\delta$}} &
$\sigma_{\mu_{\delta}}$ \\
\noalign{\smallskip}\hline\hline\noalign{\smallskip}
\multicolumn{7}{c}{Sz 19} \\
\hline\noalign{\smallskip}
HIP     & -113.& 29 &  3.& 27 & 3.07 & 2.91 \\
ACT     & -120.& 8  &  8.& 3  & 3.14 & 2.17 \\
TRC     & -108.& 8  & 10.& 9  & 1.6  & 6.1  \\
STARNET & -106.&    & 45.&    & 4.4  & 4.5  \\
\hline\noalign{\smallskip}
\multicolumn{7}{c}{RXJ\,1159.7-7601} \\
\hline\noalign{\smallskip}
HIP     & -165.& 21 & -4.& 74 & 1.73 & 1.48 \\
ACT     & -199.& 5  & -7.& 5  & 8.73 & 2.93 \\
TRC     & -188.& 8  & -8.& 2  & 2.9  & 1.9  \\
STARNET & -224.&    &-20.&    & 3.8  & 3.8  \\
\noalign{\smallskip}\hline\hline\noalign{\smallskip}
\end{tabular}
\end{center}
\end{minipage}
\begin{minipage}{8cm}
\begin{center}
\begin{tabular}{lr@{}lr@{}lll}
\noalign{\smallskip}\hline\noalign{\smallskip}
[mas/a] & 
\multicolumn{2}{c}{$\mu_{\alpha}$} &
\multicolumn{2}{c}{$\mu_{\delta}$} & 
\multicolumn{1}{c}{\raisebox{1ex}[-1ex]{$\sigma_{\mu_{\alpha}}$}
\raisebox{-1ex}[1ex]{\scriptsize \hspace*{-0.7cm}$\cos\delta$}} &
$\sigma_{\mu_{\delta}}$ \\
\noalign{\smallskip}\hline\hline\noalign{\smallskip}
\multicolumn{7}{c}{RXJ\,0837.0-7856} \\
\hline\noalign{\smallskip}
ACT     & -147.& 3 & 26.& 2 & 1.49 & 1.83 \\
TRC     & -153.& 9 & 27.& 6 & 2.1  & 1.6  \\
STARNET & -321.&   & 59.&   & 3.7  & 3.7  \\
\hline\noalign{\smallskip}
\multicolumn{7}{c}{RXJ\,1125.8-8456} \\
\hline\noalign{\smallskip}
HIP     & -545.& 22 & 12.& 13 & 0.65 & 0.55 \\
PPM     & -482.&    & 12.&    & 2.1  & 2.4  \\
ACT     & -555.& 5  & 12.& 2  & 0.87 & 1.35 \\
TRC     & -511.& 7  & 10.& 9  & 1.8  & 2.1  \\
STARNET & -388.&    &  9.&    & 3.2  & 3.2  \\
\noalign{\smallskip}\hline\hline\noalign{\smallskip}
\end{tabular}
\end{center}
\end{minipage}
\end{footnotesize}
\end{table}
