[1] In 1918, he graduated from the Grigory Shelaputin gymnasium and entered the faculty of physics and mathematics of the Moscow State University.
After receiving a stipend from the Rockefeller Foundation, Slavėnas traveled to the United States.
His doctoral advisor was Ernest William Brown, and his dissertation was on the three-body problem.
[1] During his study years in the country, Slavėnas visited (and sometimes worked at) many observatories, read science popularization lectures, communicated with Lithuanian-Americans, and published scientific press.
From 1950 to 1987 Slavėnas was chairman of the Commission for the History of Natural Sciences and Technology at the presidium of the academy.
From 1954 to 1971 Slavėnas was a member of the Council of Astronomers of the Academy of Sciences of the Soviet Union.
[2][3][1] The most important areas of Slavėnas's scientific research were the structure and evolution of the universe and stars, astrophotometric research, the basics of the theory of relativity, history and systematics of science, and the scientific worldview.