Angular Momentum Evolution and the Origin of Rotation in Stars

Ohio State University Research Foundation -Do Not Use, Columbus OH

Investigators

Abstract

PI Pinsonneault There has been extensive recent observational and theoretical work on the angular momentum evolution of low mass stars. The initial distribution of protostellar rotation rates can provide clues about the star formation process and the interaction of T Tauri stars with their circumstellar accretion disks. Rotation is intimately connected with the generation of stellar magnetic fields, and the spindown of stars can be used to study angular momentum loss from a magnetized stellar wind. Internal transport of material and of angular momentum has several sources (hydrodynamic, magnetic, and induced by gravity waves); this transport produces mixing that can strongly modify the surface abundances of stars. The sheer variety of physical effects associated with stellar rotation makes the subject complex. Fortunately, there are numerous observational constraints on theoretical models of angular momentum evolution, and recent work has established a theoretical framework for interpreting these data. This study is a combined theoretical and observational program on stellar rotation. The goals of this work are to improve the physics in models of angular momentum evolution and to provide new calibrating data for the models. ***