Olufsen, Christian Friis Rottbøll

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OLUFSEN, CHRISTIAN FRIIS ROTTBøLL

(b Copenhagen, Denmark, 15 April 1802; dCopenhagen, 29 May 1855)

astronomy.

Olufsen was the son of the Danish political economist Christian Olufsen. During his studies at the University of Copenhagen he was awarded a gold medal for a mathematical treatment of eclipses, and he later spent two years with Bessel at Königsberg. In 1829 he became senior astronomer at the University of Copenhagen and, three years later, was promoted to professor of astronomy and director of the observatory. In 1840 he received his doctorate with a dissertation on the derivation of the lunar parallax.

In 1829 Schumacher had suggested that the Royal Danish Academy of Sciences and Letters produce new tables for the sun, some preparatory work having already been done by Bessel; but more than twenty years elapsed before the tables were completed through cooperation between Hansen, in Gotha, and Olufsen. The former derived the perturbations in the movement of the earth, and the latter made comparisons with a long series of observations and the final determination of the mean motion of the earth. Olufsen’s investigation in 1831 of the systematic errors in the observations made with the Greenwich mural quadrant prerequisite for the use of the Greenwich observations of the sun for his work with Hansen.

For the series of star maps covering the declinations −15° to +15° which were intiated and published by the Berlin Academy (Akademische Sternkarten), Olufsen took over the right ascension 1^h; and he gave a detailed report on the course of the total solar eclipse of 28 July 1851, as observed from Kalmar, Sweden.

Olufsen worked in several fields, but he was often hampered by illness. His main contribution was made in connection with the work of his contemporaries, particularly that of Bessel, toward reforming and improving the foundation of astronomy.

BIBLIOGRAPHY

Olufsen’s memoris include “Untersuchungen Über den Greenwicher Mauerquadranten während Maskelynes Direction der dortigen Sternwarte,” in Astronomische Nachrichten9 (1831), 85–106; “Untersuchungen Über den Werth der Monds parallaxe, die aus den in der Mitte des vorigen Jahuhunderts angestellten correspondirenden Beobachtungen abgeleiten werden kann,” ibid., 14 (1837), 209–226; “Über die Sonnenfinsterniss am 7ten July 1842,” ibid.,22 (1844), 217–230, 232–242; and “Beobachtung der totalen Sonnenfinsterniss am 28sten July 1851 in Calmar,” ibid33 (1851), 219–222. Among his books are Disquistio de parallaxi lunae (Copenhagen, 1840), his dissertation; Tentamen de longitudine speculae Havniensis. Praemittuntur considerationes de conaminibus, quae initio seculi octavi decimi ad astronomiam practicam reformandam instituit inclytissimus Romerus(Copenhagen, 1840); Begyndelsesgrunde af astronomien med anvendelse paa den mathematiske Geographie (Cophenhagen, 1848); and tables du soleil, exécutées d’ après les ordres de la société royale des sciences de Copenhague (Copenhagen, 1853; supp., 1857), written with P. A. Hansen.