1877-1957

American astronomer who preferred developing theories to collecting data. Unlike many astronomers, Russell amassed information only to analyze specific problems. As a result of his methodology, Russell often was one of the first astronomers to announce a discovery, such as that two classes of red stars—dwarfs and giants—exist. He also theorized about stellar evolution. During annual visits to the Mount Wilson Observatory, Russell used data collected there for his research. Russell wrote a Scientific American column to popularize astronomy.