Astronomy & Astrophysics

**Table 2:** Measurements and standard deviations of the effective magnetic field of the $\beta$ Lyrae system are listed according to the year of the observations and observatory: Special Astrophysical Observatory (SAO), Crimean Astrophysical Observatory (CAO) and Osservatorio Astrofisico di Catania (OACt).
$\begin{displaymath}\begin{tabular}{rrr\vert rrr} \hline\hline \multicolumn{3}{c... ... & 790\\ & & & 51367.490 & 2260 & 730\\ \hline \end{tabular}\end{displaymath}$