Differential rotation and meridional flows of K giants: Predictions from mean field theory

摘要

We present a mean field model of the differential rotation and meridional flow of the giant star KIC 8366239. The model predicts a solar-type surface differential rotation with a total shear of 0.03 rad/d. The horizontal shear decreases with depth and vanishes at the lower boundary. No drastic increase of the rotation rate towards the core is found. The surface meridional flow is directed towards the poles and has amplitude of 26 m/s. The return flow at the bottom of the convective envelope has an amplitude of 16 m/s. The results are compared with those for the K giant Arcturus and the Sun.