\begin{table}%t2 
\caption{Stars used as radial velocity standards. Columns: 
(1) HD number (Hipparcos Catalogue field H71); 
(2) Hipparcos identifier (H1);\protect 
(3) $V$ magnitude (H5); 
(4) spectral type and luminosity class (H76); 
(5) number of spectra obtained ($N$; subtractions refer to rejected
    exposures due to detector instability); 
(6) multiplicity (G: Hipparcos acceleration binary; S: Hipparcos
    suspected non-single -- field H61)
(7) assumed radial velocity (km~s$^{-1}$; see
    Sect.~\ref{subsec:standard_stars} for details);
(8) idem from Morse et~al. (\cite{Mor91}; Table~\ref{tab:6}; Table~\ref{tab:4} for HD~23408); 
(9) radial velocity in km~s$^{-1}$ from Fekel (\cite{Fek85}; Table~\ref{tab:3});
(10) idem from Wolff (\cite{Wol78}; {\rm range} $<$$3 \cdot {\rm
     standard~deviation}$; Tables~\ref{tab:1} and~\ref{tab:3});
(11) idem from Abt \& Levy (\cite{Abt78}; Table~\ref{tab:1}); 
(12) idem from Gies \& Bolton (\cite{Gie86}; Table~\ref{tab:3}); 
(13) idem from Latham \& Stefanik (\cite{Lat82}; Table~\ref{tab:1}).}\label{tab:2}  
%%\centerline
\par
{
\begin{tabular}{rrcllcrrrrrrr} 
\hline\hline 
\multicolumn{1}{c}{HD} &
\multicolumn{1}{c}{HIP} &
\multicolumn{1}{c}{$V$} &
\multicolumn{1}{c}{SpT+LCl} &
\multicolumn{1}{c}{$N$} &
\multicolumn{1}{c}{Mult.} &
\multicolumn{7}{c}{Radial velocity [km~s$^{-1}$]}\\
\multicolumn{1}{c}{(1)} &
\multicolumn{1}{c}{(2)} &
\multicolumn{1}{c}{(3)} &
\multicolumn{1}{c}{(4)} &
\multicolumn{1}{c}{(5)} &
\multicolumn{1}{c}{(6)} &
\multicolumn{1}{c}{(7)} &
\multicolumn{1}{c}{(8)} &
\multicolumn{1}{c}{(9)} &
\multicolumn{1}{c}{(10)} &
\multicolumn{1}{c}{(11)} &
\multicolumn{1}{c}{(12)} &
\multicolumn{1}{c}{(13)}\\ 
\hline 
1438   & 1501   & 6.10 & B8V     & $3  $ & &    +3.3\phantom{$^{\rm a}$} & .       & .       & .       & .      & .     & +3.3   \\ 
3360   & 2920   & 3.69 & B2IV    & $3-1$ & &  $-$0.3\phantom{$^{\rm a}$} & $-$0.3  & .       & .       & +1.0   & .     & +0.5   \\ 
10982  & 8387   & 5.86 & B9V     & $3-1$ & &    +5.0\phantom{$^{\rm a}$} & .       & .       & +5.0    & .      & .     & .      \\ 
17081  & 12770  & 4.24 & B7IV    & $2-1$ & &   +15.4\phantom{$^{\rm a}$} & +15.4   & +14.3   & .       & .      & .     & .      \\ 
23408  & 17573  & 3.87 & B8III   & $2  $ & &    +6.5\phantom{$^{\rm a}$} & +6.5    & .       & .       & .      & .     & +7.6   \\ 
26912  & 19860  & 4.27 & B3IV    & $2-1$ & &   +14.9\phantom{$^{\rm a}$} & +14.9   & .       & .       & +15.5  & .     & .      \\ 
27638  & 20430  & 5.38 & B9V     & $2  $ &S&   +14.4\phantom{$^{\rm a}$} & .       & .       & .       & .      & .     & +14.4  \\ 
28114  & 20715  & 6.06 & B6IV    & $2-1$ & &   +12.9\phantom{$^{\rm a}$} & .       & .       & +12.9   & .      & .     & +13.4  \\ 
35708  & 25539  & 4.88 & B2.5IV  & $2  $ & &   +17.0\phantom{$^{\rm a}$} & +17.0   & +18.1   & .       & +15.2  & .     & +18.4  \\ 
36267  & 25813  & 4.20 & B5V     & $3-1$ & &   +19.8\phantom{$^{\rm a}$} & .       & .       & .       & +19.8  &  .    & .      \\ 
38899  & 27511  & 4.89 & B9IV    & $2  $ & &   +21.6\phantom{$^{\rm a}$} & +21.6   & +21.6   & +22.2   & .      & .     & +20.9  \\ 
43112  & 29678  & 5.91 & B1V     & $2  $ & &   +37.3\phantom{$^{\rm a}$} & +37.3   & .       & .       & .      & +35.8 & .      \\ 
58142  & 36145  & 4.61 & A1V     & $5-1$ & &   +26.0\phantom{$^{\rm a}$} & +26.0   & +27.2   & .       & .      & .     & +26.9  \\ 
196724 & 101867 & 4.81 & A0V     & $6-1$ &G& $-$18.4$^{a}$           & $-$12.0 & .       & .       & .      & .     & .      \\ 
196821 & 101919 & 6.08 & A0III   & $4-1$ & & $-$31.3\phantom{$^{\rm a}$} & .       & $-$31.3 & $-$31.6 & .      & .     & .      \\ 
201345 & 104316 & 7.78 & O9p     & $1  $ & &   +21.6\phantom{$^{\rm a}$} & .       & .       & .       & .      & +21.6 & .      \\ 
214994 & 112051 & 4.80 & A1IV    & $5  $ &G&    +9.1\phantom{$^{\rm a}$} & +9.1    & +7.5    & .       & .      & .     & +8.5   \\ 
217811 & 113802 & 6.37 & B2V     & $3  $ & & $-$11.2\phantom{$^{\rm a}$} & $-$11.2 & .       & .       & .      & .     & $-$10.2\\ 
219188 & 114690 & 7.06 & B0.5III & $4-1$ & &   +48.0$^{b}$           & .       & .       & .       & .      & +68.0 & .      \\ 
220599 & 115591 & 5.56 & B9III   & $2  $ & &   +12.0\phantom{$^{\rm a}$} & .       & .       & +12.0   & .      & .     & .      \\ 
\hline 
\end{tabular}}
\medskip 
$^{a}$ Fekel \cite{Fek90} (cf. Liu et~al.  \cite{Liu89}).\\
$^{b}$ SIMBAD.
\end{table}