\begin{table}%t1
\caption{Stellar parameters and chemical composition of \hechr\
  \citep{ChrGus:2003}, and two theoretical models as explained in
Sects.~2 (M~1) and~3 (M~2). The column "M~1 (initial)'' denotes the
composition of the polluting SN~ejecta; the interior of model~M~1 has
$Z=0$ throughout.}\label{t:1}
%\centering
\par
\begin{tabular}{l|rr|rr|rr}
\hline \hline
Qnty. & Value & $\sigma$ & M 1 (initial) & M 1 (final) & M 2 (initial) & M 2 (final)\\
\hline
$T_{{\rm eff}}~(K)$ & 5100 & 150 & -- & 4520 & -- & 5026\\
$\log g$ (cgs) & 2.2 & 0.3 & -- & 1.7 & -- & 2.3 \\
$M/\msun$ & $\approx$$ 0.8$ & -- & 0.820 & 0.817 & 0.810 & 0.807 \\
\noalign{\hrule}
$\logab{Fe}{H}$ & --5.3 & 0.2 & --1.3 & --5.3 & --5.3 & --5.3 \\
$\logab{C}{Fe}$ & 4.0 & 0.3 & 2.6 & 6.0 & 4.0 & 4.0 \\
$\logab{N}{Fe}$ & 2.3 & 0.2 & --0.6 & 6.2 & 0.0 & 2.9 \\
$\logab{O}{Fe}$ & 2.4 & 0.4 & 2.6 & 2.7 & 4.0 & 4.0 \\
$\Iso{12}{C}/\Iso{13}{C}$ & $\approx$$ 60$ & ($>$$ 50$) & $\approx$$ 10^6$ &
4.8 & $\approx$$ 10^6$ & 61 \\
\hline
\end{tabular}
\end{table}