\begin{table}%t1
\caption{\label{tab1}Observation summary.}
%\centering
\par
\begin{tabular}{lllll}
\hline\hline\noalign{\smallskip}
Date     &  Instrument & Filter & Airmass & Seeing \\
\hline
11/04/2009 & {\it OLT}   & $I$          &  1.7877--1.0712  &   $2.94''$   \\
28/05/2009 & {\it BUSCA} & $v,~b,~y,~I$ &  1.8827--1.0453  &   $3.09''$ \\
\hline
\end{tabular}
\end{table}