Differential rotation of the present and the pre-main-sequence Sun
Kiepenheuer-Institut für Sonnenphysik, Schöneckstrasse 6, 79104 Freiburg, Germany e-mail: kueker@kis.uni-freiburg.de; stix@kis.uni-freiburg.de
M. Stix
Received:
25
September
2000
Accepted:
9
November
2000
We present a model for the differential rotation of the present Sun as well as a solar-type star during its pre-main-sequence evolution. The model is based on the mixing-length theory of convective heat transport and a standard solar model. The resulting rotation law is in good agreement with observations and only weakly dependent on the mixing-length parameter. For the present Sun, the normalized horizontal shear decreases with increasing rotation rate, but the total shear is roughly constant. We then follow the Sun's evolutionary track from the beginning of the contraction to the arrival on the ZAMS. While at an age of 30 Myr the total shear is very similar to that of the present Sun, it is much smaller on the Hayashi track.
Key words: hydrodynamics / Sun: rotation / stars: rotation / stars: pre-main sequence
© ESO, 2001