\begin{table}%t1
\caption{The main information about the observations
for each night and each irregular satellite. In the sequence we have: the 
number of the frames~(Fr.), the mean exposure time in seconds~(Ex.), and the 
number of reference stars~(St.) used in the astrometric calibration of the 
frames. The CCD~type is given in the last column: type~I with an~array of 
the 770~$\times$ 1152~square~pixels, corresponding to 22.5~$\mu$m, and type~II 
with an~array of the 1024~$\times$ 1024~square~pixels, corresponding to~24~$\mu$m.}\label{tab1}
%\centering
\small
\begin{tabular}{l|ccccccccc}
\hline \hline
      &Himalia&Elara&Pasiphae&Sinope&Lysithea&Carme&Ananke&Leda&CCD\\
       &$(J~VI)$&$(J~VII)$&$(J~VIII)$&$(J~IX)$&$(J~X)$&$(J~XI)$&$(J~XII)$&$(J~XIII)$&type\\
~~Nights&Fr.~~~Ex.~~St.~~&Fr.~~~Ex.~~St.~~&Fr.~~~Ex.~~St.~~&Fr.~~~Ex.~~St.~~&Fr.~~~Ex.~~St.~~&Fr.~~~Ex.~~St.~~&Fr.~~~Ex.~~St.~~&Fr.~~~Ex.~~St.~~&    \\
\hline
95-May-23&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&02~~~90~~~32&~~~~~~~~~~~~&I\\
95-June-13&02~~~60~~~10&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&I\\
96-June-21&05~~~20~~118&04~~~60~~153&~~~~~~~~~~~~&~~~~~~~~~~~~~&~~~~~~~~~~~~&03~~120~~164&~~~~~~~~~~~~&~~~~~~~~~~~~&II\\
96-June-22&~~~~~~~~~~~~&04~~~60~~170&04~~120~~178&02~~180~~~205&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&II\\
96-June-24&~~~~~~~~~~~~&~~~~~~~~~~~~&02~~180~~176&02~~240~~~201&02~~240~~178&02~~300~~179&02~~300~~169&~~~~~~~~~~~~&II\\
96-June-25&04~~~60~~178&04~~180~~121&04~~180~~162&03~~240~~~164&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&II\\
96-June-26&04~~~60~~183&02~~180~~105&~~~~~~~~~~~~&~~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&II\\
96-Jul.-25&08~~~05~~~08&13~~~10~~122&~~~~~~~~~~~~&~~~~~~~~~~~~~&10~~~10~~123&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&II\\
96-Jul.-26&05~~~05~~~63&10~~~10~~111&10~~~10~~148&~~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&II\\
96-Jul.-27&10~~~05~~159&10~~~10~~133&~~~~~~~~~~~~&~~~~~~~~~~~~~&~~~~~~~~~~~~&02~~~10~~~91&~~~~~~~~~~~~&~~~~~~~~~~~~&II\\
96-Aug.-22&04~~~10~~104&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&I\\
96-Oct.-02&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~~&~~~~~~~~~~~~&02~~300~~~91&01~~~90~~122&~~~~~~~~~~~~&I\\
97-Aug.-13&~~~~~~~~~~~~&02~~180~~~15&~~~~~~~~~~~~&~~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&I\\
97-Aug.-14&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~~&02~~240~~~17&02~~300~~~14&~~~~~~~~~~~~&02~~300~~~12&I\\
97-Aug.-15&02~~~60~~~18&~~~~~~~~~~~~&04~~180~~~18&04~~240~~~~20&04~~240~~~08&02~~300~~~15&04~~300~~~15&~~~~~~~~~~~~&I\\
97-Aug.-16&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~~&02~~240~~~10&02~~300~~~09&~~~~~~~~~~~~&~~~~~~~~~~~~&I\\
98-June-05&~~~~~~~~~~~~&02~~180~~~05&~~~~~~~~~~~~&~~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&II\\
98-Sep.-03&~~~~~~~~~~~~&03~~180~~~06&~~~~~~~~~~~~&03~~240~~~~06&03~~240~~~08&02~~240~~~09&05~~240~~~06&02~~240~~~07&II\\
99-Sep.-21&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~~&02~~180~~~06&~~~~~~~~~~~~&~~~~~~~~~~~~&~~~~~~~~~~~~&II\\
\hline
\end{tabular}
\end{table}