\begin{table}%t2
\caption{Differential reddening $\Delta\ebv$ in M~52.}
\label{tab2}
\small%\centerline
{
\begin{tabular}{c|ccccccc|c}
\hline \hline
$\Delta Y (\arcmin)$&\multicolumn{7}{|c|}{$\Leftarrow\Delta X (\arcmin)\Rightarrow$}\\
$\Downarrow$ &$+15.0$&$+10.0$&$+5.0$&$0.0$&$-5.0$&$-10.0$&$-15.0$&\avgE\\
\hline
$+15.0$&$+0.22$&$+0.22$&$+0.06$&$+0.26$&$+0.29$&$+0.35$&$+0.13$&$0.22\pm0.10$\\
$+10.0$&$+0.11$&$+0.26$&$+0.24$&$+0.19$&$+0.16$&$+0.08$&$+0.11$&$0.16\pm0.07$\\
$+5.0$&$+0.05$&$+0.05$&$+0.11$&$+0.08$&$+0.18$&$+0.29$&$+0.21$&$0.14\pm0.09$\\
$~0.0$&$+0.08$&$-0.03$&$+0.05$&$~0.00$&$-0.02$&$+0.35$&$+0.06$&$0.07\pm0.13$\\
$-5.0$&$+0.08$&$+0.08$&$+0.06$&$-0.06$&$+0.06$&$+0.10$&$+0.03$&$0.05\pm0.05$\\
$-10.0$&$~0.00$&$-0.02$&$-0.06$&$+0.08$&$+0.06$&$+0.02$&$+0.11$&$0.04\pm0.08$\\
$-15.0$&$-0.03$&$-0.08$&$+0.03$&$+0.13$&$-0.05$&$0.06$&$-0.02$&$0.01\pm0.07$\\
\hline
 %& & & & & & &  \\[-8pt]
\avgE&$0.07\pm0.08$&$0.07\pm0.13$&$0.07\pm0.09$&$0.10\pm0.11$&$0.11\pm0.12$&$0.18\pm0.14$&$0.09\pm0.07$  \\
\hline
\end{tabular}}
\medskip
Notes. Uncertainties in $\Delta\ebv$ are of the order of $\pm0.05$. For absolute values: $\ebv=0.58+\Delta\ebv$. 
\end{table}