\begin{table}%t2
%\centering
\par
\caption{\label{t2}The four r\'egimes of stable or unstable nuclear burning from Bildsten (\cite{Bildsten98}),
showing the critical values of $\dot m$ that demarcate the r\'egimes.}
\begin{tabular}{rrrr}
\hline \hline
\noalign{\smallskip}
1        &   2     &   3        &4\\
CNO      &Hot CNO  &He unstable &H, He   \\
unstable &stable   &in H-rich   &stable \\
         &         &environment &        \\
\hline
\multicolumn{4}{l}{Critical values of $\dot m$:} \\
\multicolumn{4}{l}{$1\times 10^3$ g cm$^{-2}$ s$^{-1}$ (r\'egimes 1--2)}\\
\multicolumn{4}{l}{$5\times 10^3$  g cm$^{-2}$ s$^{-1}$ (r\'egimes 2--3)}\\
\multicolumn{4}{l}{$1.3\times 10^5$ g cm$^{-2}$ s$^{-1}$ (r\'egimes 3--4)}\\
\hline
\end{tabular}
\end{table}