Improved orbit for the visual-binary star 40/41 Dra

Abstract

Families of orbits of the visual binary star 40/41 Dra (ADS 11061), a near-polar visual binary star( m h J2000 00 18 = α ; 0 0 80 o J2000 ′ + = δ ) which is a wide pair in the neighborhood of the sun ( mas 19 = π t ), are calculated. Both components are spectrally binary and belong to the late spectral classes K2V and F7. The orbit was determined using a data base of photographic observations of this visual binary at the Pulkovo 26-inch refractor from 1970 through 2006. The latest spectroscopic data on the radial velocities and masses of the components are used in calculating the orbital elements. The family of orbits of 40/41 Dra was determined by the method of apparent motion parameters (AMP method) developed by Kiselev. The photographic plates were digitized and measured automatically for the first time. The parameters of the apparent motion were improved and the range of acceptable values for the true distances between the components was narrowed. The family of orbits was obtained by minimizing the O-C differences. The calculations are compared with the previously calculated family of orbits. The results of the measurements have been entered into the "Pulkovo Database of Observations of Visual Double Stars."