User:HNY2022/sandbox

Sergey Illarionovich Gaposhkin (July 12, 1898, Evpatoria, Tauride Province — September 17 , 1984, Lexington, Massachusetts) - Russian astronomer, a specialist in stellar astronomy. Was married to Cecilia Payne-Gaposhkin, with whom he conducted a number of scientific studies.

Biography
Sergey Gaposhkin was born in the family of a bricklayer. In 1917, even before finishing his education, he was called up to the Russian Imperial Army. AfterAfter the October Revolution, he joined the White Guard. The Volunteer Army, and after its defeat during the Civil War, he emigrated to Turkey in 1920.

In 1923, Gaposhkin moved to Germany. In 1927, he graduated from the University of Berlin, Russian Scientific Institute, and in 1932 he received a Ph.D. degree there.

In 1933, he moved to the United States and began working in Harvard Observatory. In 1934, he married Cecilia Payne (1900-1979), with whom he later co-authored many scientific papers.

Sergey Gaposhkin studied variable stars, and in 1938 published the book "Variable Stars", which for a long time became the only specialized monograph on this topic. That book cited the Russian text on the same topic, "Переменные звезды и способы их наблюдения", also published in 1938 (Паренаго П. and Кукаркин Б.). In 1941, he proved the duality of one of the Wolf-Rayet stars — later duality was found in about half of the stars of this class. In the late 1940s, together with six other American astronomers, he did a lot of work on analyzing photos of red dwarfs, which resulted in the discovery of flashing stars. In the 1960s, Gaposhkin and his wife explored the Cepheid s in the Andromeda galaxy and Magellanic Clouds, found that the Cepheid period decreases with increasing distance from the galactic center, and found that S-class Cepheids are 1.5 times brighter than normal Cepheids.

In 1978, he left the observatory. In 1979, his wife Cecilia Payne-Gaposhkin died. After that Sergey Gaposhkin lived in the city until his death in Lexington, Massachusetts. Sergey and Cecilia had three children. Their daughter followed in her parents ' footsteps and also became an astronomer.

Publications
Variable Stars (1938)