\begin{table}%t1
      \caption{Detected structures.}\label{tab1}
%\centering
\small
         \begin{tabular}{c c c c}
            \hline
            \hline
            \# & $\alpha_{2000}$ & $\delta_{2000}$ & $z$   \\
            \hline
1&03 32 20.08& --27 47 07.20& 0.70\\
2&03 32 16.74& --27 45 52.99& 1.00\\
3&03 32 16.51& --27 46 45.95& 1.55\\
            \hline
         \end{tabular}
   \end{table}