Rectilinear elements of visual optical double stars: With application to the 1829 southern double star catalogue of James Dunlop

The relative Rectilinear motion of optical double stars provides an important clue to the relationship of the components. We provide an objective method of confirming the optical status of double stars, and of obtaining unbiased rectilinear elements solely on data obtained from the HIPPARCOS and Gaia DR2 space missions. We apply this technique to determine the rectilinear elements of 14 optical double stars from the southern double star catalogue of James Dunlop. The resultant uncertainties are, on average, an order of magnitude smaller than the method currently used