\begin{table}%t2
\caption{Observational data for our selection of extremely metal-poor
  halo stars; \hechr\ is repeated for completeness.} \label{t:2}
%\centering
\par
\begin{tabular}{c|ccccccc|l} 
\hline \hline
Object & ${\rm [Fe/H]}$ & $T_{\rm eff}$ & $\log g$ & ${\rm [C/Fe]}$ & ${\rm
[N/Fe]}$ & ${\rm [O/Fe]}$ & ${\rm ^{12}C/^{13}C}$ & Reference \\ 
\hline
HE~0107-5240 & $-$5.30 & 5100 & 2.2 & 4.0 & 2.3 & 2.4 & 60 &
\cite{ChrGus:2003,BeChrGu:2004} \\ 
\hline
CS~22943--037 & $-$4.00 & 4900 & 1.5 & 1.2 & 2.7 & 2.0 & 4 & \cite{dhssp:2002}\\
CS~29498--043 & $-$3.75 & 4400 & 0.6 & 1.9 & 2.3 & -- & 6 & \cite{anrba:2002}\\
CS~22957--027 & $-$3.11 & 5100 & 1.9 & 2.4 & 1.6 & -- & 8 & \cite{anrba:2002}\\
CS~22892--052 & $-$2.97 & 4850 & 1.5 & 1.1 & 1.0 & 0.7 & -- &
\cite{nrb:97,sclibb:2003} \\
CS~31082--001 & $-$2.90 & 4850 & 1.5 & 0.2 & $<$$0.2$ & 0.6 & $<$$20$ & \cite{hpcbn:2002}\\
\hline 
\end{tabular}
\end{table}