Alexandr Boyarchuk (June 21, 1931 – August 10, 2015) was a Russian physicist and astronomer.
After graduation, he worked at the Crimean Astrophysical Observatory, which was under direction of the USSR Academy of Sciences at the time.
He carried out numerous studies regarding the chemical composition of stars of various classes, in particular, he discovered an excess of helium in Beta Lyrae.
Boyarchuk also studied the motion of stellar atmospheres, as well as the rotation of stars.
Based on this model, he obtained estimates of the mass, size, temperature and other characteristics of these objects.