\begin{table}%t1
\caption{\label{tab:obs}Observations log.}
%\centerline
{\begin{tabular}{llrr}
\hline\hline
Target      & Instrument & $t_{\rm exp}[{\rm s}]$ & $S/N$\\
\hline
CoRoT-Exo-2&UVES  & 2400              &200\\
HAT-P-1    &SARG  &18~000              &210\\
HAT-P-2    &SARG  & 7200              &340\\
HAT-P-4    &SOPHIE&11~000              &80\\
HAT-P-6    &SOPHIE&18~000              &180\\
HAT-P-7    &SOPHIE&14~400              &150\\
HD~17156 &SOPHIE& 3600              &220\\
HD~149026&SARG  & 7200              &420\\   
TrES-2    &SARG  &21~600              &200\\
TrES-3    &SARG  &28~800              &100\\
TrES-4    &SOPHIE&14~400              &90\\
XO-1      &SARG  &25~200              &170\\
XO-2      &SOPHIE&18~000              &110\\
\hline
\end{tabular}}\medskip
Only the total exposure times are given. The exposure times of the coadded individual spectra are mentioned in the text.
\end{table}