Dominating Molecules in the Photospheres of Cool Stars

Abstract

Molecular data bases (including very different numbers of molecular lines, and based on computations spanning a wide range in quality) have been used in the construction of models of the stellar atmospheric structure, and effects of various molecules on the stellar structure and evolution have been described in the literature. A systematic study showing which molecules are of importance in which types of stars is, nevertheless, still lacking, and the line lists used in various model computations necessarily reflect what was at hand at the time of computation rather than a systematic effort to solve the molecular opacity problem. A pioneering investigation was presented in two extensive papers by Tsuji (1964, 1973) where the foundation of the reaction scheme used in most models today was laid down. Later Tsuji (1986) has given a review of the existing work on molecules known in stars, and Johnson (1986) and Gustafsson (1989) have touched upon the same subject in reviews covering a broader range of stellar aspects. Jørgensen (1992) has recently summarized the existing molecular data (and discussed the methods used) available for model atmosphere construction.