\begin{table}   %t1 
\caption{\label{tabCenterd}Center distances, colour coefficients and mean scatter~$\sigma$ of the sub-fields.}
%\centering
\par
\begin{tabular}{cccc} 
\hline
\hline
Sub-field    & Distance from     & Colour      &    Mean standard deviation   \\
             & plate center      & coefficient &    from calibration fit      \\
	     & (degrees)         &~$a_3$       &    ~$\sigma$ (mag)                 \\ \hline
00.G &  6.5 & 0.359 & 0.077 \\
10.B & 10.4 & 0.356 & 0.087 \\
00.F & 10.6 & 0.353 & 0.091 \\
00.E & 12.4 & 0.249 & 0.098 \\
10.A & 12.7 & 0.281 & 0.083 \\
00.C & 12.8 & 0.309 & 0.120 \\
10.D & 12.8 & 0.336 & 0.112 \\
10.C & 14.1 & 0.277 & 0.088 \\
00.B & 14.3 & 0.305 & 0.110 \\
00.D & 14.4 & 0.289 & 0.089 \\
00.A & 16.2 & 0.422 & 0.096 \\     \hline
\par
\end{tabular}
\end{table}