\begin{table}%t4
\caption{\label{tab:darwin_results}Expected performance in terms of number of stars surveyed and planets characterised during the nominal 5-year mission for various telescope diameters and planet radii. }
%\centerline
 {\small \begin{tabular}{l c c c | c c}
\hline \hline
  Telescope diameter & 1-m & 2-m & 4-m & 2-m & 2-m \\
  Planet radius [$R_\oplus$] & 1 & 1 & 1 & 1.5 & 2 \\
  \hline
  \textbf{Detection}  &  &  &  &  &  \\
  Surveyed (5 years) & 89 & 303 & 813 & 590 & 921 \\
  Surveyed (2 years) & 58 & 189 & 497 & 370 & 564 \\
  \hspace{0.3 cm} \# F stars & 3 & 10 & 35 & 27 & 46 \\
  \hspace{0.3 cm} \# G stars & 11 & 43 & 136 & 96 & 164 \\
  \hspace{0.3 cm} \# K stars & 14 & 61 & 183 & 130 & 206 \\
  \hspace{0.3 cm} \# M stars & 30 & 75 & 143 & 117 & 148 \\
  \hline
  \textbf{Spectroscopy}  &  &  &  &  &  \\
  Staring (CO$_2$,O$_3$) & 20 & 64 & 199 & 132 & 234 \\
  Rotating (CO$_2$,O$_3$) & 20 & 43 & 127 & 89 & 159 \\
  \hspace{0.3 cm} \# F stars & 0 & 2 & 5 & 4 & 8 \\
  \hspace{0.3 cm} \# G stars & 2 & 7 & 25 & 17 & 36 \\
  \hspace{0.3 cm} \# K stars & 2 & 10 & 40 & 24 & 46\\
  \hspace{0.3 cm} \# M stars & 16 & 24 & 67 & 44 & 69 \\
  Staring (H$_2$O) & 15 & 32 & 101 & 71 & 121 \\
  Rotating (H$_2$O) & 11 & 21 & 60 & 48 & 83 \\
  \hspace{0.3 cm} \# F stars & 0 & 1 & 2 & 2 & 4 \\
  \hspace{0.3 cm} \# G stars & 0 & 4 & 11 & 8 & 16 \\
  \hspace{0.3 cm} \# K stars & 2 & 5 & 18 & 11 & 22 \\
  \hspace{0.3 cm} \# M stars & 9 & 11 & 39 & 27 & 41 \\
  \hline
\end{tabular}}
\medskip
All stars are assumed to host a planet in the habitable zone and to be surrounded by an exozodiacal cloud 3~times denser that in the solar system.
\end{table}