AITKEN, ROBERT GRANT ), American astronomer, was born in Jackson, Calif., on Dec. 31, 1864. He was educated at Williams college, Williamstown, Mass., from which he graduated in 1887 and received the degree of M.A. in 1892. In 1888-91 he was instructor of mathematics in Livermore college, and from 1891 to 1895 he was professor of mathematics and astronomy in the University of the Pacific. In 1895 he was appointed astronomer at Lick observatory, Mt. Hamilton, Calif., of which he was made associate director in 1923. Here he special ized in the study of double stars, of which he discovered more than 3,000. For these discoveries he was awarded in 1906 the Lalande prize by the Academy of Sciences of France. His pub lished writings include Binary Stars (1918) and numerous articles contributed to astronomical and other scientific journals.