\begin{table}%t4
      \caption{Orbital solutions for two~slightly overlapping subsets
of older and more recent primary~RVs to test the possibility of
a~secular change of the orbital period.}\label{dpdt}
%\centering
\small
\begin{tabular}{ccc}
\hline\hline
  Time interval  &  No. of &   $P$  \\
  (HJD-2~400~000)  &   RVs   &  (d) \\
\hline
13~743--34~975&104&137.9449 $\pm$ 0.0075\\
29~500--53~674&124&137.9257 $\pm$ 0.0060\\
\hline
\end{tabular}
\end{table}