A dynamical study of 12 wide visual binaries

We have carried out the first dynamical studies of the relative motions of the components of 12 wide binaries: ADS 497, ADS 2427 (GL 130.1), ADS 3593, ADS 5436, ADS 6646, ADS 6783, ADS 9559 (δ Boo), ADS 10329, ADS 10759 (ψ Dra), ADS 14878, ADS 15229, and ADS 16558. The analysis is based on series of photographic observations made with the 26-inch refractor of Pulkovo Observatory, supplemented by data from the WDS Catalog, radial velocities and HIPPARCOS parallaxes. We used the parameters of the apparent motions, which can yield the orbit and mass of a binary from observations over a short arc of the orbit of the order of 5°–10°. The orbits and masses for six stars with orbital periods from 500 to 20 000 years have been reliably determined. For five stars with periods from 2000 to 100 000 years, we obtained probable orbits and mass estimates. For ADS 497 and ADS 10329, the mass excesses in their systems are 1 and 3 M _⊙, respectively, relative to the masses expected from the mass-luminosity dependence. In three cases, for ADS 3593, ADS 14878, and ADS 16558, the obtained estimates of the total mass of the components are 46, 25, and 7300 M _⊙, respectively, if the parallaxes are correct. A perturbation with amplitude 0.3″ and period 40 yrs has been detected in the orbital motion of the system ADS 10759, possibly indicating the presence of an invisible satellite with a mass of the order of 0.4 M _⊙. The orientations of the orbits in the Galactic reference frame have been determined for all 12 binaries. The planes of most of the obtained orbits are steeply inclined to the plane of the Galaxy, as was noted in previous studies.