Australian Dictionary of Biography

Bart Jan Bok (1906-1983), astronomer, was born Bartholomeus Jan Bok on 28 April 1906 at Hoorn, the Netherlands, elder son of Jan Bok, a sergeant major in the Dutch army, and his wife Gesina Annetta, née van der Lee. He attended school at The Hague, excelling at mathematics and science, before studying astronomy at the universities of Leiden and Groningen (Ph.D., 1932). In 1929 he was awarded a fellowship to Harvard College Observatory in Massachusetts, United States of America, under the astronomer Harlow Shapley. At Troy, New York, on 9 September 1929 Bok married Priscilla Fairfield (1896-1975), an astronomer who became not only his partner but his closest scientific collaborator. On completion of his doctorate, he joined the staff of the observatory and rose through its ranks to become a full professor in 1947. Naturalised as an American citizen in 1938, he shortened his first name to Bart.

Bok’s principal research interest was the structure of the Milky Way. During the 1930s he studied the distribution and velocity of stars in the Galaxy in an attempt to determine its structure. He became an authority on the subject, even though the true spiral shape of the Galaxy was not revealed until the 1950s. With Priscilla he wrote The Milky Way (1941), widely acclaimed as one of the most successful astronomical books ever published. He also researched the small dark clouds in interstellar space that cause the absorption of starlight and showed that they consist of gas and dust that contract to form stars. The clouds are now known as `Bok globules’.

In 1956, after applying unsuccessfully for the position of director of Harvard College Observatory, Bok accepted the post of director of the Mount Stromlo Observatory and professor of astronomy at the Australian National University, Canberra. His appointment was to have a significant impact on the development of Australian astronomy. At this time Australia was a world leader in radio astronomy, principally through the work of the Commonwealth Scientific and Industrial Research Organization group in Sydney led by Joseph Pawsey, but optical astronomy lagged behind. A 74-inch (1.9 m) optical telescope had been installed at Mount Stromlo in 1955 by the previous director, (Sir) Richard Woolley, but it was through Bok’s endeavours that it became a major astronomical instrument. He forged close links with the Sydney radio astronomers and used his international contacts to attract prominent astronomers to Australia. By the early 1960s Mount Stromlo had become the leading centre for optical astronomy in the Southern Hemisphere.

Bok helped to establish the graduate program in astronomy at the ANU, the training ground for many Australian astronomers. He also recognised the need for a better observing site than Mount Stromlo and initiated a survey that resulted in the selection of Siding Spring Mountain, near Coonabarabran, New South Wales. Bok played a leading part in securing government funds for the telescopes and instruments for the new site, his efforts assisted by his friendship with Prime Minister (Sir) Robert Menzies.

Apart from his scientific achievements, Bok was an outstanding teacher and populariser of astronomy. He gave numerous public lectures, published articles in newspapers and magazines, and delivered radio broadcasts. His enthusiasm, exuberance and charisma conveyed the importance and excitement of his field to a generation of Australians. He became the public face of astronomy.

Bok worked long hours and expected others to show the same level of commitment. He believed in applying scientific principles to other areas of life and was a fierce critic of pseudo-sciences such as astrology. A pacifist and a firm advocate of international cooperation, he promoted scientific programs of the United Nations Educational, Scientific and Cultural Organization in developing countries.

In 1966 the Boks returned to the United States, where Bart was director (until 1970) of the Steward Observatory and professor of astronomy at the University of Arizona. He retired from the university in 1974. Bok received numerous awards for his contributions to astronomy: he was elected (1968) to the US National Academy of Sciences and awarded (1977) the Catherine Wolfe Bruce gold medal of the Astronomical Society of the Pacific, of which he was a board member in 1977-80. He served as vice-president (1970-74) of the International Astronomical Union and as president (1972-74) of the American Astronomical Society.

Survived by his son and daughter, Bok died on 5 August 1983 in his home at Tucson, Arizona; his body was bequeathed to the college of medicine, University of Arizona. His contribution to Australian astronomy is commemorated by the Bok prize, awarded jointly by the Astronomical Society of Australia and the Australian Academy of Science. In 1996 the Steward Observatory’s 90-inch (2.3 m) telescope was named after him.