A comparative analysis of the relative abundances of chemical elements produced in different nucleosynthesis channels in the atmospheres of the metal-rich (Fe/H >-1) Galactic-field RR Lyrae variables and in the stars of the Sagittarius dwarf galaxy, as well as in the stars of the Milky Way disk, is presented. In the Fe/H–X/Fe diagrams, the metal-rich RR Lyraes are located between two groups of comparison stars. We assume that the unusual chemical properties of the metal-rich RR Lyrae variables can be explained by their formation from the Milky Way’s matter with the addition of gas accreted from the Sagittarius dwarf galaxy.
Gozha et al. (Mon,) studied this question.