\begin{table}%ta1 \caption{\label{table.hrirosatourxrayparameters}X-ray parameters of faint HRI/{\em ROSAT} sources in $\sigma$~Orionis not listed by Caballero et~al. (2009)\tablefootmark{a}.} %%\centerline \par {\small \par \begin{tabular}{l c ccccc} \hline \hline \noalign{\smallskip} No. & Name & $N$ & $\overline{CR}$ & $\sigma_{CR}$ & $\overline{\delta CR}$ & $\chi^2$ \\ & & & [ks$^{-1}$] & [ks$^{-1}$] & [ks$^{-1}$] & \\ \noalign{\smallskip} \hline \noalign{\smallskip} 4 & Mayrit 348349 & 11 & 11.46 & 10.03 & 1.95 & 114.6 \\ % 16 & Mayrit 97212 & 11 & 3.66 & 0.95 & 1.22 & 0.361 \\ % 18 & Mayrit 403090 & 16 & 5.07 & 1.75 & 1.58 & 4.663 \\ % 27 & Mayrit 489165 & 6 & 2.77 & 1.68 & 1.24 & 2.176 \\ % 29 & Mayrit 92149 AB & 6 & 3.24 & 1.01 & 0.77 & 1.540 \\ % 31 & [W96] 4771--1056 & 6 & 3.76 & 1.00 & 1.09 & 1.126 \\ % 32 & Mayrit 374056 & 13 & 5.61 & 1.88 & 1.88 & 4.617 \\ % 37 & Mayrit 102101~AB & 7 & 7.77 & 4.86 & 1.77 & 45.91 \\ % \hline \end{tabular}} \tablefoot{\tablefoottext{a}{Number of associated X-ray events, mean and standard deviation of the net count rate, mean of the error on the count rate, and normalised double-weighted $\chi^2$ of the X-ray series (see Table~1 in Caballero et~al. 2009).}} \end{table}