\begin{table}%t1 \caption{\label{tabps}Best-fit orbital solution for {\saxj} derived from the analysis of the five outbursts observed from 1998 to~2008.} \small%\centerline { \begin{tabular}{llr} \hline \hline Parameter & Units & Value \\ \hline $T^*_{1998}$ & MJD & $50~914.79452952(85)$ \\ $P_{\rm orb}$ & s & $7249.156444(23)$ \\ $\dot P_{\rm orb}$ & $ 10^{-12}$ s/s & $3.89(15)$ \\ $a_1 \sin i / c$ & s & $0.0628106(20)$ \\ $e$ & & $<$$1.2 \times 10^{-4}$ \\ $\nu_{2008}$ & Hz & $400.9752084532(17)$ \\ $T^*_{2008}$ & MJD & 54~739.98342965 \\ \hline \end{tabular}} \medskip Note: errors are at $90\%$ c.l. on the last 2~digits. The upper limit on the eccentricity is at $95\%$~c.l. The values of $P_{\rm orb}$ and $\dot P_{\rm orb}$ are referred to~$T^*_{1998}$, while the value of $\nu_{2008}$ is referred to~$T^*_{2008}$. \end{table}