Bart Jan Bok was born in Hoorn, Holland, on 28th April, 1906. He studied at the universities of Leiden and Groningen before moving to the United States in 1929. He taught astronomy at Harvard University (1929-57) the Australian National University (1957-66) and the University of Arizona (1966-74).
Bok, who became an American citizen in 1938, was the author of The Milky Way (1941), a book which explained the structure and evolution of the Milky Way Galaxy. He also served as vice president of the International Astronomical Union (1970-76) and president of the American Astronomical Society (1972-74). Bart Bok died in Tuscan, Arizona, on 7th August, 1983.