\begin{table}%t3
\begin{minipage}[t]{\columnwidth}
\caption{The number of C~stars and M giants and C/M ratios of NGC~147.}
\label{table:3}
%\begin{center}
\par
\renewcommand{\footnoterule}{}
\begin{tabular}{c c c}
\hline\hline
    & NGC 147 & NGC 185  \\
\hline
    C  &  91            &    73         \\
    M  &  555           &    645        \\
   C/M & $0.16\pm0.02$  & $0.11\pm0.01$ \\
\hline
   C/M$^a$ & 0.154 & 0.089 \\
   C/M$^b$ & $0.24\pm0.02$ & $0.17\pm 0.02$ \\
\hline\\[-2mm]
\end{tabular}
\parbox{4.5cm}{
{$^a$ Nowotny et~al. (\cite{wnowotny03}).}\\
{$^b$ Battinelli \& Demers (\cite{battinellicb}).}}
%\end{center}
\end{minipage}
\end{table}