\begin{table}%t1
\par
\caption{\label{tab1}Light curve sampling parameters and variability amplitudes.}
\small%\centering
\par
\begin{tabular}{lccc}
\hline \hline \noalign{\smallskip}
\multicolumn{1}{l}{Light curve} &
\multicolumn{1}{c}{$T/\Delta t$} &
\multicolumn{1}{c}{Mean} & 
\multicolumn{1}{c}{ $F_{\rm var}$ } \\
 & (ks/s)  & (counts s$^{-1}$) & (\%) \\
 &  & (Soft/Hard band) &  (Soft/Hard band) \\
  \hline  
{\it XMM}/obs-201        &  92.1/100   & 7.25/0.94  & 28.78/29.56 \\ 
{\it XMM}/obs-301        &  107/100    & 7.18/0.90  & 16.71/20.51 \\ 
{\it XMM}/obs-401        &  93.2/100   & 10.04/1.34 & 20.73/23.96 \\ 
{\it XMM}/obs-501        &  118.1/100  & 8.26/1.13  & 21.86/20.65 \\ 
{\it XMM}/obs-601        &  110.1/100  & 10.59/1.39 & 35.04/35.72 \\
\noalign{\smallskip} 
RXTE/2$-$10~keV    & 1592/2 (days)    & 1.44    & 31.2 \\
{\it XMM}/OM~     &  792.5/4.3 (ks)  & $1.1\times 10^{-14}$\tablefootmark{a}   & 0.70\\
\noalign{\smallskip}\hline
\end{tabular}
\tablefoot{\tablefoottext{a}{in units of erg cm$^{-2}$ s$^{-1}$ \AA$^{-1}$.}}
\end{table}