\begin{table} %t1
 \caption{\label{tbl:obs_sum}Summary of observations for the seven analyzed fields. The mean seeing is estimated when faint stars were detected.}
 \small%\centering
\par
 \begin{tabular}{c c c c c} 
 \hline \hline  
Field & $\alpha$ & $\delta$ & Exp. time (s) & Seeing (arcsec)\\ 
 \hline 
  STAR1 & 10:00:16 & +02:16:22 & 10~350 & 0.09 \\
    STAR2 & 10:00:52 & +02:19:52 & 7650 & --\\
      STAR3 & 10:00:10 & +02:06:08 & 7650 & 0.12 \\
        STAR4 & 09:59:52 & +02:05:00 & 7170 & 0.08 \\
  STAR5 & 10:00:14 & +02:09:09 & 10~200 & 0.09 \\
    STAR6 & 10:00:02 & +02:06:57 & 7650 & 0.13\\
      STAR10 & 09:59:56 & +02:04:07 & 10~000 & --\\        
      \hline
\end{tabular}
 \end{table}