\begin{table}%t1 
\caption{\label{TAB-UCAC}UCAC2 stars in 10$\arcmin \times 10\arcmin$ fields around quasars from \mbox{ICRF-Ext2}, VCS, and VLA catalogs.}
%\centerline
 {\begin{tabular}{c c c c c c c c}
\hline
\hline
    & \multicolumn{3}{c}{UCAC2 Stars} & \multicolumn{2}{c}{$\sigma_\alpha$ (mas)} & \multicolumn{2}{c}{$\sigma_\delta$ (mas)} \\
    & $<$4 & 4--10 & $>$10 & $<$30 & $>$30 & $<$30 & $>$30  \\
\hline
ICRF-Ext2 & 123 & 168 & 425 & 360 & 249 & 404 & 205\\
VCS & 622 & 761 & 1972 & 1620 & 1190 & 1863 & 947\\
VLA & 401 & 348 & 951 & 756 & 581 & 848 & 489\\
\hline
\end{tabular}}
\par
\smallskip
The first 3 columns represent the number of quasars fields with the given number of stars from UCAC2 catalog.  
The next 4~columns denote the number of fields with the average positional errors of the UCAC2 stars $<$30~mas and $>$30~mas.
\end{table}