\begin{table}%t1 \caption{\label{Table_hd185395_stelpar}\thetacyg~stellar properties.} \small%\centerline { \begin{tabular}{l l c} \hline \hline Parameter & & \thetacyg \\ \hline Spectral type & & F4V \\ \vsini & [\kms] & 7 \\ $V$ & & 4.49 \\ $B-V$ & & $0.395 \pm 0.015$ \\ $\pi$ & [mas] & $54.54 \pm 0.15$ \\ Distance & [pc] & $18.33\pm 0.05$ \\ $M_V$ & & 3.14 \\ $[$Fe/H$]$ & & $-0.08$ \\ $T_{\rm eff}$ & [K] & 6745 \\ $\log{g}$ & & 4.2 \\ $M_1$ & [\Msun] & $1.38 \pm 0.05$ \\ Age & [Gyr] & $1.5_{-0.7}^{+0.6}$ \\ ppm ($\alpha$)$^\dagger$ & [mas~yr$^{\rm -1}$] & $-8.15$\\ ppm ($\delta$)$^\dagger$ & [mas~yr$^{\rm -1}$] & $-262.99$\\ \hline \end{tabular}} \smallskip $^\dagger$ The proper motion is affected from the orbital motion that we discuss in Sect.~\ref{sec:ao}.\\ Note: photometric and astrometric data from the H{\small IPPARCOS} catalogue (\citealt{hipparcos97,vanleeuwen07}); spectroscopic data from \citet{nordstrom04} and \citet{erspamer03}. \end{table}