\begin{table}%t3
\caption{\label{tab:others}Stellar parameters and metallicities previously derived by spectroscopy.}
%\centerline
{\begin{tabular}{lrccclc}
\hline\hline 
Star & $T_{\rm eff}$~[K] & ${\log}~g~$(cgs) & $\xi_{\rm t}$~[km~s$^{-1}$] & [Fe/H] & Source & [Fe/H] (this work)\\
\hline
CoRoT-Exo-2 & $5625\pm120$ & $4.3\pm0.2  $ & -- & $0.0\pm0.1$ & \citet{Bouchy08}& $+0.07\pm0.04$\\
HAT-P-1    &$5795\pm45$&$4.45\pm0.06$ &--&$+0.13\pm0.02$ &\citet{Bakos07a}&$+0.21\pm0.03$\\
HAT-P-2    &$6290\pm110$&$4.22\pm0.14$&--&$+0.12\pm0.08$ &\citet{Bakos07b}&$+0.49\pm0.12$\\
           &    --     &       --     &--&$+0.11\pm0.10$ &\citet{Loeillet08}&\\
HAT-P-4    &$6032\pm80$&$4.36\pm0.11$&--&$+0.32\pm0.08$&\citet{Kovacs07}&\\
           &$5860\pm80$&$\rm 4.14^{+0.01}_{-0.04}$&--&$+0.24\pm0.08$&\citet[using isochrones]{Kovacs07}&$+0.35\pm0.08$\\
HAT-P-6     &$6353\pm88$&$3.84\pm0.12$&--&$-0.23\pm0.08$&\citet{Noyes08}&\\
           &$6570\pm80$&$4.22\pm0.03$&--&$-0.13\pm0.08$&\citet[using isochrones]{Noyes08}&$-0.08\pm0.11$\\
HAT-P-7    &$6350\pm80$&${4.06\pm0.10}^a$&--&$+0.26\pm0.08$&\citet{Pal08a}&$+0.31\pm0.07$\\
HD~17156 &$6079\pm56$&$4.29\pm0.06$&--&$+0.24\pm0.03$&\citet{Fischer07}&$+0.23\pm0.04$\\
HD~149026&$6147\pm50$&$4.26\pm0.07$ &--&$+0.36\pm0.05$ &\citet{Sato05}&$+0.36\pm0.05$\\
TrES-2    &$5850\pm50$&$4.4\pm0.1$  &$1.00\pm0.05$&$-0.15\pm0.10$&\citet{Sozzetti07}&$+0.06\pm0.08$\\
TrES-3    &$5650\pm75$&$4.4\pm0.1$   &$0.85\pm0.05$&$-0.19\pm0.08$&\citet{Sozzetti09a}&$-0.10\pm0.19$\\
TrES-4    &$6200\pm75$&$4.0\pm0.1$   &$1.50\pm0.05$&$+0.14\pm0.09$&\citet{Sozzetti09a}&$+0.34\pm0.10$\\
XO-1      &$5750\pm13$&$4.53\pm0.065$&--&$+0.015\pm0.04$&\citet{McCullough06}&$-0.01\pm0.05$\\
XO-2      &$5340\pm32$&$4.48\pm0.05$ &--&$+0.45\pm0.02$&\citet{Burke07}&$+0.42\pm0.07$\\
\hline
\end{tabular}}\medskip
Only the stars analysed in the present work are listed. The last column repeats the values from Table~\ref{tab:par} to facilitate the comparison.
 $^a$ Virtually identical to the value of $4.07^{\rm +0.04}_{-0.08}$ derived using isochrones.
\end{table}