\begin{table}%t7
\caption{Photospheric and stellar parameters of \elf. We list the direct results from
  spectroscopic analyses and derived quantities (mass, luminosity, distance) from comparison with evolutionary tracks. Elemental abundances are given in mass fractions (2nd~column) and relative to solar abundances (Grevesse \& Sauval \cite{Grevesse2001} values;\protect 3rd~column).}\label{tab:results} 
%\centerline
{\small\begin{tabular}{lccc} \hline \hline 
\noalign{\smallskip}
Parameter & Result & Abundances    & Ref.\\
 & & (solar units) & \\
 \hline \noalign{\smallskip}
\Teff / K   & $140~000 \pm5000$     &                       & (1), this work \\
\logg (cgs) & $7.0  \pm0.5$          &                       & (1)           \\
\noalign{\smallskip}
H           & $\le$0.02             & $\le$0.027          & (2) \\
He          & 0.33                   & 1.3                   & (3) \\
C           & 0.48                   & 170                   & (3) \\
N           & 0.001                  & 1.2                   & this work \\
O           & 0.17                   & 22                    & (3) \\
F           & $3.2  \times 10^{-6}$   & 6.3                   & (3) \\
Ne          & 0.02                   & 11                    & (3) \\
Si          & $3.6 \times  10^{-4}$   & 0.5                   & this work \\
P           & $\le$$6.4 \times 10^{-6}$& $\le$1               & this work \\
S           & $5.0 \times  10^{-6}$   & 0.02                  & this work \\
Fe          & $\le$$3.9 \times 10^{-4}$& $\le$0.3             & this work \\
\noalign{\smallskip}
$n_{\rm H}$ / cm$^{-2}$&$1.5 \times 10^{20}$&                 & this work \\
$E(B-V$)      & 0.0                    &                       & this work \\
\noalign{\smallskip}
$M/M _\odot$& $\rm 0.60^{+.13}_{-.04}$&                          & (1) \\
$\log L /L _\odot$& $\rm 2.73^{+.41}_{-.55}$&                          & (1) \\
$d$/kpc    & $\rm 0.80^{+.22}_{-.12}$  &                           & (1) \\
\hline
\end{tabular}}
\smallskip
References:  (1) Werner \etal (\cite{Werner1991}); (2) Werner (\cite{Werner1996}); (3) Werner \etal (\cite{Werner2005}).
\end{table}