\begin{table}%t3
\par
\caption{\label{tab:orbit}Orbital parameters of both components of RS~Cha.}
\small%\centerline
{
\begin{tabular}{lcc}
 \hline\hline
Parameter & Primary component & Secondary component \\
  \hline\noalign{\smallskip}
$\Delta$HJD$^{{a}}$$_{\rm periastron}$    & 3750.5044 &  3749.6695   \\
Period (days)     &      1.66965 $\pm$ 0.00003  &  identical \\
Amplitude (km~s$^{-1}$)    &  136.4159 & 137.9077   \\
 \hline
\end{tabular}}
\smallskip
$^{{a}}$ {$\Delta$HJD~=~HJD~$-$2~450~000.0}.
\end{table}