\begin{table}%t3
\caption{\label{observcirc}Observational circumstances.}
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\noindent For convenience the data are grouped in observing runs. $r$~is the heliocentric distance in astronomical units~(AU), $\dot{r}$~the heliocentric radial velocity, $\Delta$~is the geocentric distance, $\dot{\Delta}$~the topocentric radial velocity, ``Spectro'' the spectrograph used,
$N$~is the number of individual spectra, ``Exp''~the total exposure time in thousands of seconds, 
$R=\Delta\lambda/\lambda$ the resolving power. The nominal size of the entrance slit of the spectrograph is given in arcsec. Specific values relative to individual spectra  can be found in Table~\ref{kstars}.
\end{table}