\begin{table}%t3
%\centering
\par
   \caption{The mean observed and corrected degree of polarization in comet 2P/Encke.   \label{tab3}}
   \begin{tabular}{lccccccc}
   \hline \hline
   Date 2003    & Phase angle & Area & \multicolumn{5}{c}{Polarization degree (\%)}\\
   (UT)       & ($^{\circ})$  &(km$^2$)& \multicolumn{2}{c}{642} & \multicolumn{2}{c}{662} & RX \\
                 &       &        & observed & dust only & observed & dust only & observed\\ \hline
   Nov. 20.7 & 91.12
    & 576 $\times$ 576 & 33.3 $\pm$ 2.6 & 41.6 $\pm$ 6.2 & 18.1 $\pm$ 0.6 & 42.9 $\pm$ 7.8 &\\
   Nov. 21.7 & 94.63
    & 582 $\times$ 582 & 34.9 $\pm$ 1.7 & 39.9 $\pm$ 2.9 & 22.7 $\pm$ 1.3 & 31.1 $\pm$ 1.2 & 25.1 $\pm$ 1.0\\
   Nov. 22.7 & 98.04
    & 591 $\times$ 591 & 35.8 $\pm$ 3.6\\ \hline
\end{tabular}
\end{table}