\begin{table} %t2
%\centering
\par
\caption{Explanation of comment codes.}
\label{tab:comm_codes}
\begin{tabular}{ll} \hline \hline
a & double/multiple object of comparable brightness \\
b & fainter neighbours within $0\farcs5$ \\ 
c & companions of similar brightness between $0\farcs5<r<1\farcs5$ \\ 
d & elongated \\
e & chain of compact sources \\
f & irregular \\
g & crowded \\
h & in group/association of more than 5 bright stars/clusters \\
i & irregular background \\
j & saturated star \\
k & near edge of CCD \\
l & star? \\
m & galaxy? \\ \hline
\end{tabular}
\end{table}