\begin{table}%T3
\par
\caption{\label{atmtable}Coefficients  of Eq.~(\ref{eq:atmr}):
derived in this study $B$[$\mu$as], $b$; 
predicted $B_{\rm a}$, $b_{\rm a}$ 
by atmospheric model (Lazorenko \& Lazorenko \cite{Lazorenko4});
and $B'$, $b'$ obtained from 
a single series of FORS2 images (Lazorenko \cite{Lazorenko6}). }
\small%\centerline
{
\begin{tabular}{@{}r|rr|rr|rr|rr|rl@{}}
\hline
\hline
  &\multicolumn{4}{|c|}{ FORS1 } & \multicolumn{6}{|c}{ FORS2 } \\
\hline
$k$& $B$  & $b$ & $B_{\rm a}$ & $b_{\rm a}$ & $B$   & $b$  & $B_{\rm a}$ &   $b_{\rm a}$ & $B'$ & $b'$  \\ 
\hline                 
6  & 261*  & 1.74& 31    & 1.6   &  206  & 1.19 & 92    &  1.6    & 380  & 1.2     \\  
8  & 170*  & 0.86& 27    & 1.8   &  159  & 0.94 & 79    &  1.8    & 340  & 1.2  \\                    
10 &  94  & 1.10& 14    & 1.7   &  100  & 1.18 & 41    &  1.7    & 205  & 1.6  \\                    
12 &  42  & 1.74& 13    & 1.8   &   67  & 1.40 & 37    &  1.8    & 180 & 1.7 \\                     
\hline
$T$ &\multicolumn{2}{|c|}{600 s}&\multicolumn{2}{|c|}{ 600 s}&\multicolumn{2}{|c|}{70 s} &\multicolumn{2}{|c|}{70 s} &\multicolumn{2}{|c}{17 s} \\
\hline
\end{tabular}}
\smallskip
 *  Could be biased due to the residual
effect of large image jittering. 
\end{table}