Perrine, Charles Dillon (pərĪnˈ) [key], 1867–1951, American astronomer, b. Steubenville, Ohio. He was on the staff of Lick Observatory (1893–1909) and was (1909–36) director of the Argentine National Observatory in South America. He was the first to observe (1901) the extraordinary motion (apparently faster than the speed of light) in the nebulosity about the nova in Perseus, and in 1905 he discovered the sixth and seventh satellites of Jupiter. Perrine also made special studies of comets, discovering several. Between 1900 and 1908 he accompanied four eclipse expeditions and was in charge of the one sent from Lick Observatory to Sumatra in 1901.