Circumbinary Disk Evolution in the Presence of an Outer Companion Star

We consider a hierarchical triple system consisting of an inner eccentric binary with outer companion. A highly misaligned circumbinary disk around the is subject to two competing effects: (i) nodal precession about eccentricity vector that leads increase in misalignment (polar alignment) and (ii) Kozai-Lidov (KL) oscillations inclination driven by companion reduction misalignment. The outcome depends upon ratio timescales these effects. If torque dominates, then aligns polar orientation. undergoes KL oscillations. In case, disrupted accreted binary, while some mass transferred However, when torques are similar, parts can undergo large remains close range initial inclinations evolve orientation smaller presence Disk breaking also more likely, at least temporarily, during alignment process. stellar orbits HD 98800 have parameters such expected. absence gas, solid particles unstable much radii than gas tidal truncation radius because encounters binary.