\begin{table}%t3
\caption{Observed minus calculated statistics for four major Uranus 
satellites in 1995 and Pluto observations in 2003. For Uranus 
satellites reductions, we have $\overline{({\rm O{-}C})}_x$, $\overline{({\rm O{-}C})}_y$ 
and $(\sigma_x)$, $(\sigma_y)$ that are the means and the standard 
deviations for the residuals referred to Oberon satellite. The results 
$\overline{({\rm O{-}C})}_\alpha$, $\overline{({\rm O{-}C})}_\delta$ and 
$(\sigma_{\alpha})$, $(\sigma_{\delta})$ are for 
Pluto residuals topocentric coordinates (the units are arcseconds). 
$\overline{N}_{\rm obs}$ is the mean number of observations, and 
$\overline{N}_{\rm stars}$ the mean number of reference stars used 
in the astrometric calibration of Uranus and Pluto's system.}\label{tab3}
\par
%\centering
\small
\begin{tabular}{cccc|cc}
\hline\hline
                     &Four major           &~~~~~~~~~~~~~~~~~~~~~~~~~~~~Pluto     &                              &                      & \\
                     &Uranus' satellites   &                            &                               &                      & \\
	 \hline
&&&&& \\[-8pt]
$\overline{({\rm O{-}C})}_x$ & $\overline{({\rm O{-}C})}_y$&   $\overline{({\rm O{-}C})}_\alpha$&   $\overline{({\rm O{-}C})}_\delta$   & $\overline{N}_{\rm obs}$ & $\overline{N}_{\rm stars}$\\
$(\sigma_x)$         & $(\sigma_y)$        &  $(\sigma_{\alpha})$       &   $(\sigma_{\delta})$ &       &                        \\
\hline
0$\farcs$006         & 0$\farcs$007        &    0$\farcs$043            &   --0$\farcs$012               &  743                 & 37 \\
(0$\farcs$047)       & (0$\farcs$055)      &    (0$\farcs$030)          &   (0$\farcs$019)              &                      &  \\
\hline
\end{tabular}
\end{table}