Dynamic Study of the Triple Star T Tauri

Abstract

The triple system of young stars T Tauri was discovered relatively recently and has attracted the attention of numerous researchers. Many papers have been dedicated to the study of the physical properties of the system’s stars, which are surrounded by a disk of dust and gas. Our work is focused on the astrometric analysis of this triple system using the method of apparent motion parameters (AMP). Currently, the orbit of the inner pair Sa-Sb with a period of 27 years is well-established. Based on the Gaia DR3 parallax, its total mass MSa + Sb=2.49M⊙. Relying on the published high-precision uniform observations with the Keck 1 and VLT telescopes, we employed the AMP method to derive two orbits for the outer pair N-S, one of which is almost circular. For a circular orbit, it is possible to calculate the orbital elements and dynamic parallax for a given mass solely using the apparent motion parameters. This enabled a comparison between the dynamic parallax and the high-precision parallax from the Gaia DR3 catalog, facilitating the calculation of masses of each component based on the mass of the inner subsystem: MN=(2.4±0.2)M⊙, MSa=(2.09±0.05)M⊙, MSb=(0.40±0.05)M⊙. The boundaries for the orbital period were estimated to be 500⩽P⩽700 years.