The role that ionization plays in the formation and evolution of a star, from the creation of a proto star by gravitational collapse of a molecular cloud, Hayashi track, main-sequence, red giant phase and latter stellar evolution phases, is still a great unknown.
Moreover, we don’t know the contribution that such processes have for the variation of the star's angular momentum, the creation of stellar magnetic fields and the formation of planetary discs. These are only a few of the many questions that we need to answer to have a better understanding of the fluid dynamics affecting the evolution of a star.
Ana Brito and Ilídio Lopes have recently announced a new result that links the two main rotational regimes for F stars on the main sequence with the location of the base of their convective envelopes and the region where the heavy elements ionize.
The work was published in the Monthly Notices of the Royal Astronomical Society and introduces the possibility of exploring further the connection between ionization processes and the observable macroscopic properties of stars. Particularly promising are the consequences of this study to understand the complex mechanisms related to the formation of internal magnetic fields, and the mechanisms of redistribution of angular momentum in stars.
Read more in "The partial ionization zone of heavy elements in F-stars: a study on how it correlates with rotation", A. Brito, I. Lopes, Monthly Notices of the Royal Astronomical Society, 488, 1558 (2019).