\begin{table}%t1 \caption{\label{t:widths}Nuclear data for the two steps of the $3\alpha$-reaction.} %\centering \par \begin{tabular}{ccccc} \hline \hline\noalign{\smallskip} Nucleus&$J^{\pi}$&$E_R$ (keV)&$\Gamma_{\alpha}$ (eV)& $\Gamma_{\gamma}$ (meV) \\ \hline\noalign{\smallskip} $^8$Be&$0^+$& $91.84 \pm 0.04$&$5.57 \pm 0.25$ &$-$ \\ $^{12}$C&$0^+_2$&$287.6 \pm 0.2$& $8.3\pm1.0$ &$3.7\pm0.5$ \\[2pt] \hline \end{tabular} \tablefoot {See text for the definitions of the quantities.\vspace*{-2mm}} \tablebib{\citep{TKG04,Ajz90,audi03}.} \end{table}