\begin{table}%t3
\caption{ {\it BeppoSAX} and {\it XMM-Newton} observation log.}\label{t3}
%\centerline
 {
\begin{tabular}{llllllllll}
\hline
\hline
  &  Date & & \multicolumn{3}{l}{Exposure time $^a$ (ks)} &  &
                                    \multicolumn{3}{l}{Count rate $^b$ ($10^{-3}$ ct s$^{-1}$)} \\
\hline
\hline
{\it SAX} & 2001 Dec.  14--18 &  & LECS & MECS & PDS &  & LECS & MECS & PDS   \\
\cline{4-6}\cline{8-10}
 & & & 42.92 & 131.83 & 58.11 & & $2.23$ & $3.76$ & $<18.0$  \\
\hline
{\it XMM} & 2002 June 27--28 &  & MOS1/2 & PN &     &  & MOS1/2 & PN  \\
\cline{4-5}\cline{8-9}
  &  &  & 57.1 & 48.3 & & & $\sim 0.013$ & $0.04$  \\
\hline
\end{tabular}
}
\par
\smallskip
\par
$^a$ On-source net exposure time. The LECS exposure time is considerably shorter than 
that of the MECS, because the LECS could operate only when the spacecraft was not 
illuminated by the Sun.
\par
$^b$ Background-subtracted source count rates, with photon counting statistics errors. 
For the PDS the $90\%$ upper limit is given.
\par
\end{table}