\begin{table}%t1
%\renewcommand{\arraystretch}{1.2}
%\centering
\par
\caption{The RXTE observation IDs of the observations that are included in each track, the HC and SC of their vertices, and the distance, $S_{\rm shift}$, over which each track is shifted relative to track~1. Average flux at the vertex ($S_{\rm a}=2$), start time of the first and end time of the last included observations and the total included observation time are also indicated. Note that tracks 3, 10a-c and 11a-b do not show a vertex. All dates are in the year 1998; typical errors in HC are $\sim$0.01, in $\rm SC\sim0.03$, in $S_{\rm shift}\sim0.01$ and in flux at $S_{\rm a}=2\sim43$.\label{ptracks}}
\begin{tabular}{cccccccccc}
\hline
\hline
Track&\multicolumn{3}{c}{Vertex}&Flux at $S_{\rm a}=2$&\multicolumn{2}{c}{Observation ID}&$t_{\rm start}$ (UTC)&$t_{\rm end}$ (UTC)&$t_{\rm obs}$\\
nr&HC&SC&$S_{\rm shift}$&(cnts s$^{-1}$ PCU$^{-1}$)&\multicolumn{2}{c}{of included observations}&\multicolumn{2}{c}{month-day hours:min}&(ks)\\
\hline
1&0.46&3.07&0.00&$768.2\pm43.3$&30051-01-01-01&30051-01-01-00&05-17 11:01&05-17 20:57&28\\
2&0.53&3.13&0.092&$857.1\pm47.8$&30051-01-02-00&30051-01-03-00&05-21 12:39&05-24 19:21&29\\
   &&&&&30051-01-03-01&30051-01-03-02&&&\\
3&-&-&-&-&30051-01-04-00&30051-01-04-01&05-28 08:33&05-28 14:30&2\\
4&0.54&3.10&0.085&$864.2\pm53.7$&30051-01-05-00& &06-01 09:60&06-01 17:40&28\\
5&0.60&3.27&0.249&$824.4\pm36.2$&30051-01-06-00&30051-01-07-00&06-05 05:16&06-09 12:42&25\\
   &&&&&30051-01-07-01&30051-01-07-02&&&\\
6&0.51&3.14&0.086&$829.2\pm49.9$&30051-01-08-00&30051-01-08-01&06-13 01:26&06-17 15:29&110\\
   &&&&&30050-01-01-00&30050-01-01-01&&&\\
   &&&&&30050-01-01-02&30050-01-01-03&&&\\
   &&&&&30050-01-01-04&30050-01-01-050&&&\\
7&0.51&3.14&0.086&$837.3\pm50.7$&30050-01-01-05&30050-01-01-06&06-17 15:58&06-20 10:19&69\\
   &&&&&30050-01-01-07&30050-01-01-080&&&\\
   &&&&&30050-01-01-08&30050-01-02-00&&&\\
   &&&&&30050-01-02-01&30050-01-02-02&&&\\
   &&&&&30050-01-02-03&&&&\\
8&0.46&3.08&0.010&$756.0\pm50.0$&30051-01-09-00&30051-01-09-01&06-26 09:34&06-29 16:09&41\\
   &&&&&30051-01-10-00& &&&\\
9&0.66&3.30&0.305&$842.7\pm20.6$&30051-01-11-00&30051-01-11-01&07-03 14:22&07-09 15:40&78\\
   &&&&&30051-01-11-02&30051-01-11-03&&&\\
   &&&&&30051-01-12-00& &&&\\
10a&-&-&-&-&30051-01-12-01&&07-13 09:36&07-13 15:39&22\\
10b&-&-&-&-&30051-01-12-02&&07-31 15:11&07-31 18:59&14\\
10c&-&-&-&-&30050-01-03-00&&08-09 13:31&08-09 17:25&14\\
11a&-&-&-&-&30050-01-03-01&&08-14 13:18&08-14 17:55&17\\
11b&-&-&-&-&30050-01-03-02&&08-21 13:02&08-21 16:11&11\\
12&0.49&3.14&0.076&$829.7\pm33.6$&30050-01-03-03& &10-10 01:45&10-10 06:44&18\\
\hline
\end{tabular}
\end{table}