\begin{table}%t2
\caption{Excerpt from the observations list, available only in electronic form at the CDS. From left to right: the name 
of satellites; the time in Julian Date (UTC); and the  right 
ascension and declination coordinates, given in degree and fraction. These 
topocentric observed positions of two satellites refer to a mean 
equator and equinox~J2000 system.}\label{tab2}
\par
%\centering
\small
\begin{tabular}{cccc}
\hline\hline
Satellite & Date & Right ascension & Declination \\
\hline
Phobos&2~452~872.752084491&341.2239091&--15.1838285\\
Deimos&2~452~872.752084491&341.1953815&--15.1843957\\
Phobos&2~452~872.754208333&341.2234622&--15.1838686\\
Deimos&2~452~872.754208333&341.1946309&--15.1846936\\
Phobos&2~452~872.755233796&341.2232502&--15.1838743\\
Deimos&2~452~872.755233796&341.1943158&--15.1848254\\
\hline
\end{tabular}
\end{table}