\begin{table}%t1
\caption{\label{centerf}For the three VIMOS fields observed: coordinates (J2000),
number of slits ($N$) and exposure times.}
\small%\centering
\par
\begin{tabular}{ccccc}
\hline\hline
Field number & $\alpha$   &  $\delta$ & $N$ & Exp. time \\
             & (deg)   & (deg) &   & (s)  \\
\hline
1 &   194.72     &   27.87              & 322 &  7200  \\ 
2 &   194.69     &   28.14              & 298 &  7184  \\ 
3 &   195.04     &   27.72              & 306 &  7098  \\ 
\hline
\end{tabular}
\end{table}