wichita.edu
…of stars, such as globular clusters; in the search for understanding of the chemical enrichment of old star populations.
“Constraints on the Distance Moduli, Helium, and Metal Abundances, and Ages of Globular Clusters from Their RR Lyrae and Non-variable Horizontal Branch Stars. II. Multiple Stellar Populations in 47 Tuc, M3, and M13”, Denissenkov, Pavel…
https://www.wichita.edu/profiles/academics/fairmount_college_of_liberal_arts_and_sciences/Physics/Faculty/Ferguson-Jason.php