Visual Orbit, Differential Photometry, and Dynamical Mass of DG Leo

摘要

A new orbital solution with a significantly improved accuracy for the elements, differential photometry, and dynamical mass is presented for the visual binary DG Leo, which consists of a spectroscopic binary and a δ Scuti star. Some dynamical and astrophysical implications of the newly obtained results are discussed. In particular, due to possibly coinciding inclinations of the visual and spectroscopic orbits, both their coplanarity and common retrograde motion should be evaluated. Differential photometry data confirm that the three stars have approximately the same mass of about 2 M⊙. The Hipparcos parallax is only marginally compatible with the obtained dynamical parallax of 4.91 mas, which is suggested as a more reliable distance estimate (~204 pc) for this pair.