\begin{table}%t1
%\centering
\par
\caption{Relevant astronomical and astrophysical parameters used
in the text. The value for the Sun's angular momentum $J$ has been
obtained from (Pijpers \cite{Pijpers2003}). The planetary data can be retrieved
at {\tt http://nssdc.gsfc.nasa.gov/planetary/factsheet/}. }
    \label{astropar}
\begin{tabular}{cccc}
            \hline\hline
Symbol & Description & Value & Units\\
            \hline\noalign{\smallskip}
$G$ & Newtonian gravitational constant & $6.67259\times 10^{-11}$ & m$^3$ kg$^{-1}$ s$^{-2}$\\
$c$ & speed of light in vacuum & $2.99792458\times  10^8$ & m s$^{-1}$\\
$GM$ & Sun's GM & $1.32712440018\times  10^{20}$ & m$^3$ s$^{-2}$\\
$R$ & Sun's equatorial radius & $6.9599\times  10^8$ & m\\
$J$ & Sun's proper angular momentum & $1.9\times  10^{41}$ & kg m$^2$ s$^{-1}$\\
AU & astronomical unit & $1.49597870691\times  10^{11}$ & m\\
$a_{\rm Mer}$ & Mercury's semimajor axis & 0.38709893 & AU\\
$a_{\rm Ven}$ & Venus's semimajor axis & 0.72333199 & AU\\
$a_{\rm Ear}$ & Earth's semimajor axis & 1.00000011 & AU\\
$a_{\rm Mar}$ & Mars's semimajor axis & 1.52366231 & AU\\
$e_{\rm Mer}$ & Mercury's eccentricity & 0.20563069 & --\\
$e_{\rm Ven}$ & Venus's eccentricity & 0.00677323 & --\\
$e_{\rm Ear}$ & Earth's eccentricity & 0.01671022 & --\\
$e_{\rm Mar}$ & Mars's eccentricity & 0.09341233 & --\\
$\epsilon_{\rm Mer}$ & Mercury's inclination to the ecliptic & 7.00487 & deg\\
$\epsilon_{\rm Ven}$ & Venus's inclination to the ecliptic & 3.39471 & deg\\
$\epsilon_{\rm Ear}$ & Earth's inclination to the ecliptic & 0.00005 & deg\\
$\epsilon_{\rm Mar}$ & Mars's inclination to the ecliptic & 1.85061 & deg\\
            \hline
         \end{tabular}
\end{table}