\begin{table}%t1
%\centering
\par
\caption{Mean heliocentric radial velocities derived from different ions
compared to those derived by ZSW.}\label{radvelo}
\small \begin{tabular}{lcr}
\hline     \hline \noalign{\smallskip}
Ion & $\varv_{\rm rad}$ & $\varv_{\rm rad}^{\rm ZSW}$ \\ 
 & (km~s$^{-1}$) & (km~s$^{-1}$) \\
 \hline
$[$Fe~{\sc ii}] & 156.9 & 141.0 \\
$[$O~{\sc i}] & 156.1 & 164.0 \\
Si~{\sc ii} & 155.7 & 150.0 \\
Fe~{\sc ii} & 159.9 & 144.0 \\
Cr~{\sc ii} & 161.1 & -- \\
Balmer lines & 152.8 & 143.0 \\
H$\alpha^{\rm ca}$ & 150.9 & 126.0 \\
H$\alpha^{\rm bp}$ & 110.0 & 70.0 \\
H$\alpha^{\rm rp}$ & 197.0 & 210.0 \\
    \hline
  \end{tabular}
\end{table}