Otto Struve - Research

Research

In 1937, Struve discovered a phenomenon which was later named the Struve-Sahade effect (S-S effect), that is the apparent weakness of lines of the secondary star in massive binary stars when the secondary is receding. This effect poses problems for the accurate reconstruction of the separated primary and secondary spectra. The same year, he discovered interstellar hydrogen in ionized form.

By 1959, Struve has published more than 900 journal articles and books, that places him one of most prolific astronomers (Probably only Ernst Öpik published more, with 1094 items). Many of those works aimed at popularizing astronomy. In particular, he published 39 articles (and 10 other items) in Popular Astronomy (1923–1951, the journal was discontinued in 1951), 154 in Sky and Telescope (1941–1963, the journal was started in 1941) and 83 reviews of books and works by other astronomers. Most of his co-authored scientific articles were co-authored with Pol Swings and were dedicated to spectroscopical studies of peculiar stars. To explain his interest in this topic, Struve once noted that he never seen a spectrum of a star where he couldn't find anything to work on.

Struve's major discoveries were detection of stellar rotation and dependence of the rotational speed on the stellar spectral class (temperature). They spurred the development of stellar evolution theory. In addition to stellar rotation, he also studied Stark effect in stellar spectra, that is broadening of the spectral lines by the electric field in the stellar atmosphere. He also worked on the turbulence of stellar atmosphere and expanding shells around stars. This topic required a larger telescope than those available to him. Therefore, between 1933 and 1939, he built a 82-inch telescope at the McDonald Observatory, which was then the second largest telescope in the world (after the Mt. Wilson 100-inch (2.5 m) telescope).