\begin{table}%t1
\par
\caption {\label{Tparam}Comet 67P model parameters.}
%\centerline
 {\begin{tabular}{l c}
\hline\hline
 Shape &  Lamy et~al.  2007  Resolution: 3$^0$ ($\simeq$30~m.)\\
 Mean nucleus radius & $r_{\rm c}\equiv{}$2 km \\
 Rotation mode &  uniform, retrograde, fixed-axis OZ \\
 Rotation period &  12.55~h\\
 Subsolar point  &  +20$^0$ from equatorial plane$^\dagger$\\
 Visible albedo &  $A_V =0.052$ \\ 
 IR emissivity &  $\epsilon = 0.9$\\
 Heliocentric distance &  $r_h = 3$ AU\\
 Internal heat flux (shadow) &   $F_s = 0.05 c_\odot/r_h^2$\\
 $\rm H_2O$ production     &solar-driven  sublimation with uniform $f=0.07$\\
 Computed  $\rm H_2O$ production&$ Q = (4.75 {-} 7.06) \times 10^{26}$ molec/s\\
 $\rm CO$ production  & surface diffusion (non-uniform, $A_0 =  0.2$ )\\
 Computed $\rm CO$ production&  $Q = (1.05 {-} 1.08) \times 10^{27}$ molec/s\\
 \hline
\end{tabular}}
\tablefoot{The symbol $c_\odot$ denotes the solar constant, and $f$ is the surface icy area fraction. $\dagger$ This angle is the 2006 value and may be different during the 2014 rendez-vous.}
\end{table}