\begin{table}%t1
%\centering
\par
\caption {\label{table:1}Stellar parameters of  HD~47~186 and HD~181~433. The rotational period is derived from the 
activity index log~$R^{'}_{HK}$.}                 
\begin{tabular}{l l l l}       
\hline\hline                 
Parameters & HD~47~186 & HD~181~433 & Reference  \\   
\hline      
Spectral type  & G5V & K3IV    & Hipparcos \\
Parallax [mas] & 26.43 & 38.24 & Hipparcos \\
Distance [pc]  & 37.84 & 26.15 & Hipparcos \\
$m_v$          & 7.6   &  8.4  & Hipparcos \\
$B-V$            & 0.71  &  1.01 & Hipparcos \\
$M_v$          & 4.74  &  6.31 & Hipparcos \\
Luminosity [$L_\odot$]  & 1.08~$\pm$~0.029 & 0.308~$\pm$~0.026 & Sousa et~al. (\cite{sousa08}) \\
Mass [$M_\odot$]  & 0.99 & 0.78 &  Sousa et~al. (2008) \\
$T_{\rm eff}$ [K]  & 5675~$\pm$~21   & 4962~$\pm$~134 & Sousa et~al. (\cite{sousa08}) \\
log~$g$         & 4.36~$\pm$~0.04 &  4.37~$\pm$~0.26 & Sousa et~al. (\cite{sousa08}) \\
$\rm [Fe/H]$         & 0.23~$\pm$~0.02 & 0.33~$\pm$~0.13  & Sousa et~al. (\cite{sousa08}) \\
{\vsini} [\kms]  & 2.2 & 1.5 & this paper \\
log~$R^{'}_{HK}$  & --5.01 & --5.11 & this paper \\
$P_{\rm ROT}$ [days]  & 33  & 54 & this paper \\
\hline                                   
\end{tabular}
\end{table}