\begin{table}%t5
%\centering
\par
\caption{\label{T3}Astrophysical properties of 31~Comae. }
\begin{tabular}{lll}
\hline\hline \noalign{\smallskip}
Parameter & Value   & Based on  \\
 \hline 
$V_0$, mag & 4\fm935  & APT $V$ photometry      \\
Distance, pc & 89.1$^{+1.9}_{-1.7}$  & revised {\em Hipparcos} \\
$M_V$ & $+0\fm19\pm0.05$ & from $V_0$ and distance \\
Classification, MK & G0III &  Gray et~al. (\cite{Gray et al 2001}) \\
Temperature, K & 5810 &  Gray et al. (\cite{Gray et al 2001}) \\
                            & $5660 \pm 42$ &  STELLA spectra  \\
Radius, $R_\odot$           & $8.74 \pm 1.1$  & angular diameter \\
Minimum radius, $R_\odot$   & $8.95 \pm 0.27$ & from $P_{\rm rot}$ \& $v\sin i$\\
Luminosity, $L_\odot$       & $73.2 \pm 4$  & from $M_V$ and B.C. \\
& $77.7 \pm 13$  & from $R$ and $T_{\rm eff}$ \\
Gravity, cgs & 3.42        & Gray et~al. (\cite{Gray et al 2001})\\
 & $3.51 \pm 0.09$  & STELLA spectra \\
Mass, $M_\odot$             & $2.6 \pm 0.1$ & evolutionary tracks \\
Age, Myr              & $540^{+24}_{-21}$  & isochrone fitting \\
Metallicity, [M/H] & $-$0.21  &  Gray et~al. (\cite{Gray et al 2001})   \\
                            & $-$0.17 &  GC, Str\"omgren phot.  \\
                            & $-$$0.15\pm0.03$ &  STELLA spectra   \\
Li abundance, $H=12$          & $3.0 \pm 0.15$ & STELLA spectra \\
Average RV, \kms            & $+$$0.10\pm$0.33 & STELLA spectra\\
$v\sin i$, \kms             & $67 \pm 2$ & STELLA spectra \\
Rotation period, days       & $6.80 \pm 0.06$ & MOST photometry\\
                            & $7.04 \pm 0.12$ & APT $y$ photometry \\
                            & $6.76 \pm 0.02$ & STELLA radial velocity \\
Inclination, deg            & $\approx$80 & adopted \\
 \hline
\end{tabular}
\tablefoot{Values not cited in the third column were obtained in this
paper. GC=Geneva-Copenhagen survey.}
\vspace*{-3.5mm}
\end{table}