Luther, C. Robert

(b. Schweidnitz, Germany [now Swidnica, Poland], 10 April 1822; d. Düsseldorf, Germany, 15 February 1900)

astronomy.

Luther was the son of F. H. A, August Luther and the former Wilhelmine von Ende. In 1831–1841 he attended the secondary school of his native town. From 1841 to 1843 he studied natural sciences, especially astronomy, at the University of Breslau and continued these studies at Berlin in the fall of 1843. As a student of Encke’s, Luther soon began doing computations for the Berliner astronomisches Jahrbuch which published his work from 1849 to 1899. From 1847 he was an observer at the Berlin observatory; in 1848 he reduced Encke’s meridian circle observations; and beginning in 1850 he succeeded Galle at the nine-inch refractor. In 1851 he followed Brünnow as director of the small observatory at Bilk, a suburb of Düsseldorf, remaining in Düsseldorf until his death.

Luther’s lifework was the planetoids; he discovered twenty-four with priority and many others which had been discovered independently about the same time. For several of these planetoids he calculated the ephemerides continuously; these ephemerides are among the best and most accurately calculated ones for planetoid. The work deserves to be appreciated because at first Luther had only a telescope with a six-foot focal length at Bilk (in 1877 he acquired a larger one) and made all his observations with a nonilluminated ring micrometer. In the last years of his life Luther restricted his work to the reduction of observations that, because of his defective vision, were made by his son Wilhelm.

Luther received many honors, including an honorary doctorate from the University of Bonn (1855). The Astronomische Nachrichten, from volume 21 (1844) to volume 152 (1900), contains many, mostly short, notes by Luther.

Luther married Caroline Märker in 1859; they had a son, Wilhelm.

BIBLIOGRAPHY

Luther’s writings, besides the notes in Astronomische Nachrichten, include Hora O Berliner akademische Sternkarten(Berlin, 1857); and “Neuberechnung der Barker’ schen Hilfstafel,” in Encke’s new ed. of Olbers’ Methode eine Kometenbahn zu berechnen (Weimar, 1847).

An obituary is V. Knorre, in, Vierteljahrsschrift der Astronomischen Gesellschaft, 17 (1900), 191-200.

H.-Christ. Freiesleben