Study of the Binary Star ADS 7251 by Observations on the 65-cm Refractor at Pulkovo from 1962-2018

Results are presented from a study of the binary star ADS 7251 (STF 1321) based on a uniform series of observations on the 65-cm refractor at Pulkovo from 1962 through 2018. The errors in the yearly average positions ρ and θ are equal to 0′′.004 and 0°.02 for the photographic and 0.”003 and 0.°01 for the CCD observations. A new orbit is calculated from the found relative position and the exact parallax of Gaia. The comparisons use modern observations of Hipparcos and Gaia, as well as observations from the distant past in the nineteenth century by Struve. This study yielded better convergence with the distant observations when the Gaia parallax was used. The errors calculated from O-C are 0′′.008 ÷ 0′′.011 . They are comparable to those obtained for other binary stars close to the sun, as well as to the corresponding estimates for stars rotating around the central body of the galaxy and observed on the Keck and VLT telescopes. The importance of observations of the components A and B of ADS 7251 as possible parent stars for exoplanets is noted.