\begin{table}%T3
%\centering
\par
\caption{\label{ast-calib} Our observations of $\alpha$ Psc that employ
 an astrometric calibration derived from images of the Trapezium
 cluster core, compared to the prediction of the ephemerides from
 Scardia (\cite{Sca83}). The mean residuals were used as a
 correction for the ephemerides. In this way the measurements of
 Gliese 22 before 1995 were put into a consistent system of pixel
 scale and detector orientation.}
\begin{tabular}{lllllllll}
\hline\hline
Epoch & Telescope & Instrument & \multicolumn{2}{c}{Measured}
 & \multicolumn{2}{c}{Predicted} &
  \multicolumn{2}{c}{Residuals} \\ 
 & & & \multicolumn{2}{c}{(calibrated with Trapezium)} &
  \multicolumn{2}{c}{(Scardia \cite{Sca83})} \\
  & & & PA [deg] & $d$ [arcsec] & PA [deg] & $d$ [arcsec] & $\Delta$PA &
  $\Delta d $\\ \hline
% {\bf $\alpha$ Psc} & & & & & & \\
1995.526 & ESO NTT & SHARP~II & 275.8 $\pm$ 0.1 & 1.848 $\pm$ 0.005 &
  276.5 & 1.868 & --0.7 & --0.020 \\
1996.641 & ESO 3.6-m & ADONIS & 274.5 $\pm$ 0.1 & 1.870 $\pm$ 0.008 &
  275.8 & 1.861 & --1.3 & 0.009 \\
1997.8843 & CA 3.5-m & MAGIC & 274.8 $\pm$ 0.2 & 1.838 $\pm$ 0.012 &
  275.0 & 1.853 & --0.2 & --0.015 \\
1999.6681 & CA 3.5-m & OMEGA Cass & 273.1 $\pm$ 0.1 & 1.852 $\pm$ 0.004 &
  273.8 & 1.842 & --0.7 & 0.010 \\ \hline
 & & & & & & mean residuals & --0.7 $\pm$ 0.2 & --0.004 $\pm$ 0.008 \\
 \hline
\end{tabular}
\end{table}