\begin{table}%t4
\caption{Sources detected in the ACIS-I observation of
the NGC~6251 field, within 4$\arcmin$ from the core.
\label{tab3}}
%\begin{center}
{\begin{tabular}{lccc} 
\hline \hline
\# & $\alpha_{{\rm 2000}}$ & $\delta_{{\rm 2000}}$ & count rate \\
& & & ($10^{-4}$~s$^{-1}$) \\ \hline
1 & $16^{\rm h}32^{\rm m}31\fs8$ & $+82^{\rm h}32^{\rm m}16^{\rm s}$ & $810 \pm 20$$^a$ \\
2 & $16^{\rm h}33^{\rm m}00\fs5$ & $+82^{\rm h}31^{\rm m}12^{\rm s}$ & $4.8 \pm 1.8$ \\
3 & $16^{\rm h}33^{\rm m}21\fs3$ & $+82^{\rm h}31^{\rm m}56^{\rm s}$ & $5.6 \pm 1.8$ \\
\hline 
\end{tabular}}
$^a$ NGC~6251 nucleus.
%\end{center}
\par
\end{table}