\begin{table}%t3
%\centering
\par
\caption{Coordinates and magnitudes of the comparison stars.\label{tab3}}
\begin{tabular}{rcccccccc}
\hline\hline
\multicolumn{1}{c}{Id} &\multicolumn{1}{c}{$\alpha_{2000}$}&\multicolumn{1}{c}
{$\delta_{2000}$}&\multicolumn{1}{c}{$V$}&\multicolumn{1}{c}{$n_{V}$}&
\multicolumn{1}{c}{$B$}&\multicolumn{1}{c}{$n_{B}$}&
\multicolumn{1}{c}{$I$}&\multicolumn{1}{c}{$n_{I}$}\\
\hline
\multicolumn{9}{c}{Field A}\\
1253~~~& 5 22 57.93 & $-$70 31 31.96 &$16.889\pm0.026$ & 14&$17.575\pm0.045$&
14&$16.102\pm0.025$&14\\
\multicolumn{9}{c}{Field B}\\
 128~~~& 5 16 29.75 & $-$71 01 46.62 &$16.194\pm0.023$ & ~15&$16.888\pm0.037$
&14&$15.410\pm0.035$&14\\
\hline
\end{tabular}
\end{table}