\begin{table}%T2
\par
  \caption{\label{tab:positions}Estimated detached-shell radii ($R_{\rm shell}$) of warm
    carbon stars exhibiting a cool MgS~feature in their SWS~spectra,
    based on the relation in Eq.~(\ref{eq:centr_dist}) between the
    "30''~$\mu$m feature centroid position and the size of the
    shell. }
  %\begin{center}
\par
  \begin{tabular}{l l c c}
    \hline
    \hline
    \multicolumn{1}{c}{Source}& 
    \multicolumn{1}{c}{${{m}_{\rm bol}}^{1}$}&
    \multicolumn{1}{c}{${\lambda_{\rm C,30}}^{2}$ [$\mu$m]}& 
    \multicolumn{1}{c}{$R_{\rm shell}$ [$^{\prime\prime}$]}
    \\
    \hline
    \object{W Ori} & 2.87 & 31.3 & 8\\
    \object{S Cep} & 3.15$^\dagger$ & 31.2 & 6\\
    \object{T Dra} & 4.94 & 30.2 & 1.6\\
    \object{V Cyg} & 3.24$^\dagger$ & 30.5 & 4\\
    \object{RU Vir}& 4.24$^\dagger$ & 30.4 & 2\\
    \hline
\end{tabular}%\end{center}
\par
%\medskip
$^1$Bolometric magnitude from 
    \citet{2002AetA...390..967B}. $^2$Centroid positions taken from
    \citet{2002AetA...390..533H}. $^\dagger$Average of the listed
    values.
 \end{table}