V471 Tauri - A three-body orbit

Abstract

A model is proposed for V471 Tauri to explain the apparent period changes currently assigned to this K2 V + white dwarf eclipsing system. It is shown that the light-time effects of a model in which the eclipsing pair orbits with an as yet undetected third body can fit the observed eclipse timings. The model features a constant period P1 = 0.52118334 days for the eclipsing pair, with the third-body orbit of period P0 = 24.6 yr, eccentricity e = 0.36, and probably of low inclination. Present observations imply an upper limit to the third-body mass of about 0.8 solar mass. Possibilities of detecting this component by IR observations, visual inspection, or speckle interferometry are discussed.