\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}