\begin{table}%t2
\caption{\label{t:obs}Observational log.}
%\centerline
 {\begin{tabular}{ccccc}
\hline\hline
Date & UT (end) & Airmass & Seeing & Dataset ID \\ 
& (h:m:s) &  & ($''$) & (FORS2.2002-08-)\\
\hline
12/08/2002 & 04:09:42 & 1.383 & 0.98 & 12T04:09:42.883 \\
           & 04:36:32 & 1.347 & 0.88 & 12T04:36:32.163 \\
           & 05:11:55 & 1.316 & 0.71 & 12T05:11:55.313 \\
           & 05:38:44 & 1.303 & 0.66 & 12T05:38:44.081 \\
13/08/2002 & 03:14:54 & 1.483 & 1.15 & 13T03:14:54.375 \\
           & 03:41:41 & 1.425 & 1.03 & 13T03:41:41.247 \\
14/08/2002 & 01:37:57 & 1.822 & 1.03 & 14T01:37:57.100 \\
           & 02:04:44 & 1.699 & --    & 14T02:04:44.521 \\
           & 02:32:36 & 1.594 & --    & 14T02:32:36.985 \\
           & 02:59:27 & 1.513 & 0.72 & 14T02:59:27.785 \\
           & 03:30:20 & 1.439 & 0.77 & 14T03:30:20.610 \\
           & 03:57:08 & 1.39  & 0.85 & 14T03:57:08.873 \\
\hline                  
\end{tabular}}
\medskip
For each observation the exposure time is 1560~s.
\end{table}