EDDINGTON, SIR ARTHUR STANLEY (1882— ), British astronomer, was born at Kendal, England, Dec. 28, 1882. He was educated at Owen's college, Manchester, and Trinity college, Cambridge, where he was Senior Wrangler in 1904 and Smith's Prizeman in 1907. In the latter year he was elected fellow of his college. From 1906 to 1913 he held the post of chief assistant at the Royal observatory at Greenwich; and in 1913 he became Plumian professor of astronomy at Cambridge. In 1914 he was made director of the observatory at Cambridge, and in the same year was elected fellow of the Royal Society.
He is a member of many British and foreign scientific societies and was awarded the Hopkins prize of the Cambridge Philosophi cal society (1918-21), the Pontecoulant prize of the French academy (1919), the gold medal of the Royal Astronomical society (1924), the Bruce medal of the Astronomical Society'of the Pacific (1924), and the Henry Draper medal of the National academy of sciences (1924). He was knighted in 193o.
Eddington's principal researches are on the motions of stars, stellar evolution and relativity. His first published paper in 1906 was on the systematic motion of stars; this was followed during the next nine years by a series of papers on the structure of the heavens. "The Systematic Motions of the Stars of Professor Boss's Preliminary General Catalogue" appeared in 191o; in this paper Eddington analysed this catalogue of 6,188 stars and some of his later researches are based on this analysis. In 1916-17 he published papers on "the radiative equilibrium of the stars," dealing with the interior of a star. Eddington grasped the sig nificance of the theory of relativity at an early stage of its develop ment, and, by means of articles, books and lectures, gave a clear exposition of the theory. His own contribution to this theory is em bodied in a paper published in 1921 on "a Generalisation of Weyl's Theory of the Electromagnetic and Gravitational Fields." He collaborated in this Encyclopedia. He received the O.M. in 1938. His published works include Stellar Movement and the Structure of the Universe (1914), Report on the Relativity Theory of Gravita tion (1918), Space, Time and Gravitation (192o), The Mathematical Theory of Relativity (1923), Stars and Atoms (1927), The Expanding Universe (1933) • (See ASTRONOMY.)