\begin{table}%T1
%\centering
\par
\caption{\label{obs_AC_table} Overview of all observations of Gliese~22~AC
 used for the visual orbit determination in this paper. Except for the
 first two data points all observations have been carried out at the
 3.5-m telescope on Calar Alto.}
\begin{tabular}{lllllllll}
\hline\hline
No. & Date & Epoch & Position & Projected & Weight & Filter &
 Flux ratio & Instrument \\ 
    &      &       &  angle [$^{\circ}$] & separation [mas] & & &
 $F_{{\rm C}}/F_{{\rm A}}$ & (or reference) \\ \hline
1 & 12.10.1989 & 1989.7803 & 42.7 $\pm$ 2.5 & 451 $\pm$ 20 & 4 & $K$ & 
  0.167 $\pm$ 0.009 & McCarthy et al. (\cite{Mcc91}) \\
2 & 10.12.1989 & 1989.9418 & 43.9 $\pm$ 2.5 & 453 $\pm$ 20 & 4 & $H$ & 
  0.143 $\pm$ 0.008 & McCarthy et al. (\cite{Mcc91}) \\
3 & 11.09.1990 & 1990.6954 & 57.1 $\pm$ 6.3 & 405 $\pm$ 39 & 5 & $K$ & 
  & 1D  \\
4 & 20.09.1991 & 1991.7201 & 71.6 $\pm$ 1.6 & 443 $\pm$ 13 & 5 & $K$ & 
  & 1D  \\
5 & 30.09.1993 & 1993.7474 & 122.5 $\pm$ 0.5 & 464 $\pm$ 11 & 7 & $K$ &
  0.151 $\pm$ 0.004 & MAGIC \\
6 & 28.01.1994 & 1994.0767 & 129.3 $\pm$ 4.3 & 478 $\pm$ 40 & 10 & $K$ &
  & MAGIC \\
7 & 15.09.1994 & 1994.7064 & 141.1 $\pm$ 0.4 & 510 $\pm$ 5 & 9 & $K$ &
  0.141 $\pm$ 0.007 & MAGIC \\
8 & 13.12.1994 & 1994.9501 & 145.2 $\pm$ 0.2 & 532 $\pm$ 5 & 9 & $K$ &
  & MAGIC \\
9 & 08.10.1995 & 1995.7693 & 157.5 $\pm$ 1.7 & 526 $\pm$ 16 & 9 & $K$ &
  0.158 $\pm$ 0.004 & MAGIC \\
10 & 28.09.1996 & 1996.7448 & 172.1 $\pm$ 0.2 & 533 $\pm$ 4 & 10 & $K$ &
  0.141 $\pm$ 0.004 & MAGIC \\
11 & 17.11.1997 & 1997.8789 & 190.2 $\pm$ 0.3 & 460 $\pm$ 4 & 7 & $K$ &
  0.171 $\pm$ 0.008 & MAGIC \\
12 & 09.02.2001 & 2001.1095 & 302.3 $\pm$ 0.3 & 334 $\pm$ 4 & 9 & $K$ &
  0.185 $\pm$ 0.005 & OMEGA Cass \\
13 & 03.11.2001 & 2001.8406 & 325.5 $\pm$ 0.5 & 402 $\pm$ 6 & 8 & $K$ &
  0.151 $\pm$ 0.011 & OMEGA Cass \\
14 & 19.10.2002 & 2002.7994 & 348.2 $\pm$ 0.4 & 463 $\pm$ 5 & 9 & $K$ &
  0.150 $\pm$ 0.005 & OMEGA Cass \\
  \hline
\end{tabular}
\end{table}