\begin{table}%t1
\caption{\label{tab:totobs}Summary of the observations used in this survey.}
%\centering
\par
\begin{tabular}{lllll}
\hline\hline \noalign{\smallskip}
Year & Date & Filter & Number & Exposure time \\
\hline
2002 & 25 Jun.--15 Aug. & $R$ & 63 & 600  \\
2005 & 26 Jul.--25 Aug. & $R$ & 204 & 720 \\
2005 & 26 Jul.--25 Aug. & $B$ & 3 & 720 \\
2005 & 26 Jul.--25 Aug. & $I$ & 3 & 720 \\
\hline
\end{tabular}
\end{table}