\begin{table}%t4
%\centering
\par
   \caption{Aperture polarization results for comet 2P/Encke.   \label{tab4}}
   $$
   \begin{tabular}{lccrr@{$~\pm~$}l}
   \hline \hline
   Nov. & Filter & Area & Phase & $P$ & $\sigma
   P$\\
   2003   &   &                    & angle\\
   (UT) & & (km$^2$) & ($^{\circ}$)~~  & \multicolumn{2}{c}{ (\%)}\\ \hline
   \multicolumn{5}{c}{2.6-m telescope}\\ \hline
   21.718 & $R$ & 2916 $\times$ 4471 & 94.52 & 7.7 & 1.8\\
   23.792 & $R$ & 2991 $\times$ 4587 &101.63 & 6.7 & 1.0\\
   24.718 & $R$ & 3035 $\times$ 4654 &105.01 & 9.8 & 1.1\\ \hline
   \multicolumn{5}{c}{1.25-m telescope}\\ \hline
   17.765 & $U$ & $\pi \times 5679^2$ & 80.75 & 8.06 & 0.12\\
   & $B$ & && 7.66 & 0.11\\
   & $V$ & && 10.42 & 0.12\\
   21.719 & $U$ & $\pi \times 5831^2$ & 94.51 & 7.23 & 0.14\\
   & $B$ & && 16.40 & 0.58\\
   & $V$ & && 5.00 & 0.11\\
   22.747 &$ U$ & $\pi \times 5896^2$ & 98.04 & 7.48 & 0.09\\
   & $B$ & && 7.85 & 0.08\\
   & $V$ & && 5.53 & 0.09\\
   23.728 & $U$ & $\pi \times 5983^2$ & 101.42 & 7.28 & 0.08\\
   & $B$ & && 7.43 & 0.08\\
   & $V$ & && 9.12 & 0.07\\ \hline
\end{tabular}
$$
\end{table}