\begin{table}%T1
%\centering
\small
\caption{Log of \Swift\ XRT observations.}
 \label{grb050721:obs}
%{\scriptsize
\begin{tabular}{cccccc}
\hline\hline
Sequence & Obs. mode    & Start time          & End time            & Exposure  & Time since trigger \\ %\hline
         &              & yyyy-mm-dd hh:mm:ss & yyyy-mm-dd hh:mm:ss & s         & s             \\
\hline
%(1) & (2) & (3) & (4) & (5)  & (6)\\ \hline
00146970000 &   XRT/IM  & 2005-07-21 04:32:20 & 2005-07-21 04:32:22 & 2.5       &     186       \\
00146970000 &   XRT/WT  & 2005-07-21 04:32:28 & 2005-07-21 05:48:30 & 205       &     194       \\
00146970000 &   XRT/PC  & 2005-07-21 04:34:38 & 2005-07-21 05:50:49 & 1291      &     324       \\
00146970001 &   XRT/PC  & 2005-07-21 09:00:03 & 2005-07-21 19:01:44 & 8818      &   16249       \\
00146970003 &   XRT/PC  & 2005-07-22 00:05:07 & 2005-07-22 23:42:59 & 19169     &   70554       \\
00146970004 &   XRT/PC  & 2005-07-23 11:27:27 & 2005-07-24 13:13:58 & 5937      &  197894       \\
00146970005 &   XRT/PC  & 2005-08-28 14:50:42 & 2005-08-29 08:52:59 & 8600      & 3320489       \\
\hline
 \end{tabular}
 %}
 \end{table}