\begin{table}%t2
\caption{Bl\"ocker track time scales: PN~visibility is
defined as between $\log T_{\rm eff} = 4.4$ and either a~nebular age $t = 10^4~\rm yr$ or a~stellar luminosity $\log L = 3.0$, whichever occurs earlier.}\label{time}
%\centering
\small
\begin{tabular}{llll}
\hline \hline 
  Mass  [$M_\odot$]  & $t_{\rm start}$ [yr]  & $t_{\rm end}$ [yr] &
 $t_{\rm visibility}$ [yr] \\
\hline
0.546 & $90 \times 10^3$  & -- & -- \\
0.565 & $4 \times 10^3$   & $10 \times 10^3$   & $6 \times 10^3$\\ 
0.605 & $1.5 \times 10^3$ & $7.4 \times 10^3$ & $5.9 \times 10^3$\\ 
0.625 & 660         & $3.6 \times 10^3$  &  $2.9 \times 10^3$\\ 
0.696 & 100         & 880           & 780 \\
0.836 & 100         & 840           & 740 \\
0.940 & 12          & 90            & 78 \\
\hline
\end{tabular}
\end{table}