\begin{table}%t1
\caption{OAN errors in the instrumental system and colour indices of the comparison stars 
in the standard system (season 2003).}\label{tab:errors}
%\centering
\par
\begin{tabular}{ccccc}
\hline  \hline
 Season & Filter $u$ & Filter $v$ & Filter $b$ & Filter $y$ \struut \\
\hline
 OAN 2002 & 0.031 & 0.012 &  0.008 &  0.008\struutup \\
 OAN 2003 & 0.024 & 0.005 &  0.006 &  0.006\struutdown \\
\cline{1-5}
 Star &  $V$ ($\sigma_{V}$) & ($b-y$) ($\sigma_{b-y}$) & m1 ($\sigma_{m1}$) & c1 ($\sigma_{c1}$) \struut \\
\hline
 C1 &  7.394 {\small (20)}&  0.583 {\small (11)}&  0.326 {\small (28)}&  0.346 {\small (45)}\struutup  \\
 C2 &  7.358 {\small (20)}&  0.291 {\small (11)}&  0.144 {\small (28)}&  0.473 {\small (45)} \\
 C3 &  6.729 {\small (20)}&  0.097 {\small (11)}&  0.282 {\small (28)}&  0.563 {\small (45)}\struutdown \\
\hline
\end{tabular}
\end{table}