MIXING DUE TO ANGULAR-MOMENTUM TRANSFER IN EVOLVING SUN-LIKE STARS

The physical mechanisms that control the rotational history of stars like the Sun are reviewed, and the likely role of the associated rotational mixing is described. Results of stellar evolution calculations that include the effects of rotation are also described. The same theory, based on a single calibration for stars of different masses and metallicities, can successfully explain the observed Li and Be depletion in young open clusters and Li in field dwarf stars of the halo population, and the striking difference between metal-rich and metal- poor abundance patterns. There is evidence, both observational and theoretical, that angular momentum remains hidden in stellar interiors into advanced phases of evolution. Internal rotation also offers a natural explanation for the CNO isotopic anomalies observed among red giants. Finally, some of the questions raised by recent progress are considered.