Samuil Kaplan and the development of astrophysical research at the Lviv University (dedicated to the 100th anniversary of his birth)

TL;DR

This paper reviews Samuil Kaplan's influential astrophysical research at Lviv University (1948-1961), highlighting his scientific contributions across multiple fields and his role in developing observational techniques and infrastructure.

Contribution

It provides a comprehensive overview of Kaplan's work during his Lviv period, including unpublished archival materials and a complete bibliography, emphasizing his foundational impact on astrophysics.

Findings

Kaplan's work advanced theories in stellar evolution and cosmic plasma physics.

He developed observational techniques for artificial satellite tracking.

His research laid groundwork for future astrophysical studies.

Abstract

Samuil Kaplan (1921-1978) was a productive and famous astrophysicist. He was affiliated with a number of scientific centers in different cities of former Soviet Union. The earliest 13 years of his career, namely in the 1948-1961 years, he worked in Lviv University in Ukraine (then it was called the Ukrainian Soviet Socialist Republic). In the present paper, the Lviv period of his life and scientific activity is described on the basis of archival materials and his published studies. Kaplan arrived in Lviv in June 1948, at the same month when he obtained the degree of Candidate of science. He was a head of the astrophysics sector at the Astronomical Observatory of the University, was a professor of department for theoretical physics as well as the founder and head of a station for optical observations of artificial satellites of Earth. He was active in the organization of the astronomical observational site outside of the city. During the years in Lviv, Kaplan wrote more than 80 articles and 3 monographs in 9 areas. The focus of his interests at that time was on stability of circular orbits in the Schwarzschild field, on white dwarf theory, on space gas dynamics, and cosmic plasma physics, and turbulence, on acceleration of cosmic rays, on physics of interstellar medium, on physics and evolution of stars, on cosmology and gravitation, and on optical observations of Earth artificial satellites. Some of his results are fundamental for development of theory in these fields as well as of observational techniques. The complete bibliography of his works published during the Lviv period is presented. Respective scientific achievements of Samuil Kaplan are reviewed in the light of the current state of research in these areas.