\begin{table}%t1
%\centering
\par
\caption{Observing log of imaging observations with the Hubble Space Telescope, and relative astrometry of the binary components as derived from the observations.}
         \label{obslog}
\begin{tabular}{rccllrl}
\hline \hline
            Date & MJD & Prog.\ ID  & Instrument (filters)     &  sep & PA & Reference  \\
                 &     &  GO  &                 & [mas] & [$\deg$] &  \\
            \noalign{\smallskip}
            \hline
            \noalign{\smallskip}
2\ Jun. 1998   & 50~966.3 & 7952 & NIC1 ({\it F110M, F145M, F165M})   &$275.0\pm2.0$&  $41.0\pm0.2$& Mart\'{\i}n et~al.\ (1999a) \\
24\ Jun. 1998  & 50~988.6 & 7830 & NIC3 ({\it F187N})   &--$^a$ & --$^a$ & Mart\'{\i}n et~al.\ (1999a) \\
4\ Mar. 2001   & 51~972.6 & 8720 & WFPC2 ({\it F675W, F814W})  &$246.0\pm20.0^b$& $23.0\pm2.0^b$& Bouy et~al.\ (2003)\\
16\ Jun. 2001  & 52~076.4 & 9157 & WFPC2 ({\it F606W, F814W})   &$255.4\pm2.8$&  $18.3\pm0.3$& Bouy et~al.\ (2003)\\
3\ Jan. 2002   & 52~277.8 & 9157 & WFPC2 ({\it F606W, F814W})  &$252.1\pm2.8$&  $13.7\pm0.3$&This paper \\
25\ Apr. 2002  & 52~389.5 & 9157 & STIS/CCD ({\it MIRVIS}) &$250.0\pm6.6$&  $11.4\pm0.8$&This paper \\
8/9\ Jun. 2002& 52~433.9 & 9345 & WFPC2 ({\it F606W, F814W})  &$247.6\pm2.8$&   $9.8\pm0.3$&This paper \\
30\ Dec. 2002  & 52~638.7 & 9345 & WFPC2 ({\it F606W, F814W})  &$243.6\pm2.8$&   $5.7\pm0.3$&This paper \\
29\ Dec. 2003  & 53~002.7 & 9968 & WFPC2 ({\it F606W, F814W})  &$239.2\pm2.8$& $356.7\pm0.3$&This paper \\
            \noalign{\smallskip}
            \hline
\end{tabular}
\begin{list}{}{}
\item[$^{{a}}$] NIC3 pixel scale of $\approx$200~mas/pixel is too coarse
to derive meaningful relative astrometric measurements of the binary components.
\item[$^{{b}}$] The binary was not centered on the detector, but located
close to the bordering region between the PC-CCD and one of the WF-CCDs (edge
of imaging pyramid), which resulted in larger uncertainties in the relative astrometry.
\end{list}
   \end{table}