\begin{table}%t3
      \caption{\label{spectra}Spectral parameters for a power law fit to the monthly HESS~data.}
%\centerline
{\small
\par
\begin{tabular}{lccccccccccccc}
            \hline
            \noalign{\smallskip}
           Period &$\overline{MJD}$ & $\Delta^{+}_{\overline{MJD}}$ & $\Delta^{-}_{\overline{MJD}}$ & $\tau$ & $\theta$ & $\phi$ & $\Gamma$ & $\Phi_{0}$ & $F_{E}$ & $L_{\gamma}$ & $\chi^{2}$/ndf & $P_{\chi^{2}}$\\
\noalign{\smallskip}
	 & [d] & [d] & [d] & & & & & [$10^{-12}$~TeV$^{-1}$~cm$^{-2}$~s$^{-1}$] & [$10^{-12}$~erg~cm$^{-2}$~s$^{-1}$] & [$10^{32}$~erg~s$^{-1}$] & &\\
            \hline
	2004 & 53104.4 &... &... &... &... &... & $2.7\pm0.2$  & $1.3\pm0.1$ & $3.0\pm0.9$ & $8\pm2$ & 2.3/5 & 0.81\\
	\hline
	2007 & & & & & & & & & &\\
 	May &  54~235.1 & 5.7 & 6.3 & $-74$ & $-0.38$ & $-0.060$ & $2.6\pm0.5$ & $0.7\pm0.2$ & $1.4\pm0.4$ & $4\pm1$ & 2.374/3 & 0.50\\
 	June & 54~263.1 & 5.7 & 8.3 & $-46$ & $-0.35$ & $-0.037$  & $3.8\pm0.5$ & $1.5\pm0.2$ & $3.0\pm0.4$ & $8\pm1$ & 1.352/3 & 0.72\\
 	July & 54~291.9 & 8.0 & 7.1 & $-17$ & $-0.25$ & $-0.014$ & $2.7\pm0.3$ & $1.3\pm0.4$ & $2.5\pm0.6$ & $7\pm2$ & 1.294/3 & 0.73\\
        \hline 
	Total$^{**}$ & 54~262.5 &... &... &... &... &... & $2.8\pm0.2$ & $1.1\pm0.1$ & $2.2\pm0.6$ & $6\pm2$ & 4.678/5 & 0.46\\
	 \hline
         \end{tabular}}
         \smallskip
\par
For the periods April and August, no spectrum could be obtained due to low statistics: Mean Modified Julian Date $\overline{MJD}$, $\Delta^{+-}_{\overline{{MJD}}}$ date range, days relative to periastron $\tau$, true anomaly $\theta$, orbital phase (mean anomaly) $\phi$, Photon index $\Gamma$, flux normalisation $\Phi_{0}$, mean energy flux $F_{{E}}$ and \g-ray luminosity $L_{{\g}}$ above $1~\mbox{TeV}^{{\rm *}}$, ~$\chi^{2}$ per number of degrees of freedom $\frac{\chi^{2}}{\rm{ndf}}$ and probability $P_{\chi^{2}}$ for the fit are shown. Shown are statistical errors only.\\
$^{*}$ Monthly values for $F_{{E}}$ and $L_{{\g}}$ in 2007 have been computed assuming a fixed photon index of $\Gamma=2.8$.\\
$^{**}$  Entire HESS~dataset from April to August 2007.
\end{table}