US astronomer who discovered and observed
thousands of double stars.
From 1895 onwards he worked at the Lick Observatory on Mount Hamilton,
California, and was its director 1930-35.
Aitken was born in Jackson, California. In 1891 he became professor
of mathematics at the University of the Pacific.
He began a survey of double stars 1899, not finished until 1915. During
the early years of the project he was assisted by W J Hussey
(1862-1926), and between them they discovered nearly 4,500 new binary
systems. Their primary tool was the 91-cm/36-in refractor. Aitken then
carried out a thorough statistical examination of this vast amount of
information, which he published as Binary Stars 1918 and, revised, as
New General Catalogue of Double Stars 1935.
His work lay not merely in the discovery of new binary stars, but also
in determining their motions and orbits.