\begin{table}%t1
\caption{Summary of observations.}
\label{obs.tab}
\small%\centerline
 {
\begin{tabular}{cccccc}
\hline \hline
&&&&& \\[-8pt]
Epoch    & Int. Time & Freq. & Band.$^a$ & Samp. & $S_{\rm max}$$^b$ \\
(MJD)    & (s)       & (MHz)     & (MHz)     & $\mu$s  & (mJy) \\
\hline
54~217.98 & 1800      & 385       & 10 / 0.16 & 102.4   & 4   \\
54~218.01 & 1800      & 1380      & 60 / 0.32 & 102.4   & 0.4 \\
54~218.89 & 1800      & 1380      & 60 / 0.32 & 102.4   & 0.4 \\
54~245.74 & 3600      & 1380      & 60 / 0.32 & 102.4   & 0.3 \\
\hline
\end{tabular}}
\medskip
$^a$ Total usable bandwidth/channel bandwidth. \\
$^b$ For the observation at 385~MHz this is the upper limit on 400-MHz flux density~$S_{400}$.  For the other three observations at 1380~MHz, this is the upper limit on the 1400-MHz flux density~$S_{1400}$.
\end{table}