Dyson, Frank Watson (1868-1939)

English astronomer. He was especially interested in stellar motion and time determination. He was one of a number of astronomers who confirmed the observations of Jacobus Kapteyn on the proper motions of stars, which indicated that the stars in our Galaxy seemed to be moving in two great streams. These results were later realized to be the first evidence for the rotation of our Galaxy. He initiated the public broadcasting of time signals by the British Broadcasting Corporation over the radio in 1924. He was knighted in 1915 and made a KCB in 1926.

Dyson organized several expeditions to study total eclipses of the Sun, including that of 1919, which first verified the relativity shift predicted by Einstein. Other areas to which he made important contributions include the study of the Sun's corona and of stellar parallaxes. With R van der Riet Woolley he wrote Eclipses of the Sun and Moon 1937. He was president of the International Astronomical Union 1928-32, and was elected Fellow of the Royal Society 1901.

Dyson was born in Ashby-de-la-Zouch, Leicestershire, and was educated at Bradford and Cambridge. He was chief assistant at the Royal Observatory, Greenwich 1894-1906, Astronomer Royal for Scotland 1906-10, and Astronomer Royal for England 1910-33.