How to change the relative inclination in a triple star system - naive numerical experiments with tidal dissipation

Staffan Söderhjelm

For stable hierarchical triple systems with large relative inclination, the Kozai cycle gives episodes of high eccetnricity.With a simplistic model for the tidal dissipation, one may induce a shrinking of the inner orbit, and thus a diminishing of its angular momentum. The conservation of the total angular momentum then prescribes an inclination-change, and the observed changes are seen to follow closely the very simple theoretical predictions. Although the inspiration for this work was to shed light on Algol's nearly perpendicular orbit-planes, there seems to be no special features at 90 degrees that could act to 'trap' the relative inclination.