\begin{table}%t2
%\centering
\par
\caption{\label{tabrms}RV rms and peak-to-peak amplitude (in m/s) and relative rms photometry for the three periods.}
\begin{tabular}{cccc}
\hline \hline\noalign{\smallskip}
 &  rms RV & ampl RV & rms phot\\ \hline
All & 2.40  & 10.8  & $3.6\times 10^{-4}$\\
Low & 0.44  &  1.9 & $1.2\times 10^{-4}$\\
High & 1.42  & 8.0  & $4.5\times 10^{-4}$\\ \hline
\end{tabular}
\end{table}