Dreyer, Johan Ludwig Emil
Johan Ludwig Emil Dreyer (yō´hän lŏŏt´vĬkh ā´mēl), 1852–1926, Danish astronomer, b. Copenhagen, who worked in Great Britain. He was assistant astronomer at the earl of Rosse's observatory, Parsonstown (now Birr), Ireland (1874–78), and at the observatory of the Univ. of Dublin (1878–82) and director (1882–1916) of the observatory at Armagh. He compiled the standard New General Catalogue of Nebulae and Clusters of Stars (1888; supplements, 1895, 1908), wrote a biography of Tycho Brahe (1890) and History of the Planetary Systems from Thales to Kepler (1906), and edited Second Armagh Catalogue of 3,300 Stars (1886), the scientific papers of Sir William Herschel (1912), and the first volumes of the collected works of Tycho Brahe (15 vol., 1913–29).