HANSEN, JENS ANDERSEN (1806-18 7 7 ), Danish poli tician, was born on Jan. 7, 1806, at Odense. He was a master shoemaker, but later became the editor of the weekly democratic paper Almuevennen (1842), and of the Morgenposten (1856-64). In 1849 he became the leader of the liberal peasants party, whom he represented in the Reichsrat from 1856-66. An opponent of the Eiderdanen, he fought continually for the improvement of the conditions of the peasants.
He wrote Vor For f ataings Historie 1848 til 1866 (2 vols., 72), Memoirenbruchstiick, mit lies Historie og Gjerning (r875). HANSEN, PETER ANDREAS Danish astronomer, was born on Dec. 8, 1795, at Tondern, in the duchy of Schleswig. He learned the trade of a watchmaker, but in 18 20 went to Copenhagen, where he won the patronage of H. C. Schu macher. He acted as Schumacher's assistant in work connected with the Danish survey, chiefly at the new observatory of Altona, 1821-25. Thence he passed on to Gotha as director of the Seeberg observatory. Hansen studied the problems of gravita tional astronomy. A research into the mutual perturbations of Jupiter and Saturn secured for him the prize of the Berlin Academy in 183o, and a memoir on cometary disturbances was crowned by the Paris Academy in 185o. In 1838 he published a revision of the lunar theory, entitled Fundamenta nova investi gationis, etc., and the improved Tables of the Moon based upon it were printed in 1857, at the expense of the British government, and were immediately adopted in the Nautical Almanac, and other Ephemerides. A theoretical discussion of the disturbances em bodied in them (still familiarly known to lunar experts as the Darlegung) appeared in the Abhandlungen of the Saxon academy of Sciences in 1862-64. Hansen received the Royal Astronomical Society's gold medal in 1842, and communicated to that society in 1847 a paper on a long-period lunar inequality (Memoirs Roy. Astr. Society, xvi.), and in 1854 one on the moon's figure (lb. xxiv.). He was awarded the Copley medal by the Royal Society in 185o, and his Solar Tables, compiled with the assistance of Christian Olufsen, appeared in 1854. Hansen gave in 1854 the first intimation that the accepted distance of the sun was too great by some millions of miles (Month. Notices Roy. Astr. Soc. xv. 9). He died on March 28, 1874, at the new observatory in Gotha, erected under his care in 1857.
See Vierteljahrsschrift astr. Gesellschaft, x. Month. Notices Roy. Astr. Society, xxxv.; Proc. Roy. Society, xxv.; R. Wolf, Geschichte der Astronomic, Wochenschrift fur Astronomic, xvii. (account of early years by E. Heis) ; Allgemeine deutsche Biographic (C. Bruhns) .