Heinrich Louis d'Arrest
Heinrich Louis d'Arrest ( born August 13, 1822 in Berlin, † June 14, 1875 in Copenhagen ) was a German - Danish astronomer who worked in Germany and Copenhagen. He discovered several comets, the asteroid (76 ) Freia and 342 deep-sky objects. In addition, he was co-discoverer of the planet Neptune. He is primarily known for his research on comets and asteroids, but also significantly involved in the decryption of galaxy clusters.
D' arrest ancestors were French Huguenots who had fled in 1685 after revocation of the Edict of Nantes to Germany.
D' Arrest studied mathematics at the University of Berlin. During this time he undertook astronomical calculations and observations of the heavens. On 9 July 1844, he observed a comet, whose discovery was, however, awarded the French Mauvais, who had two days earlier perceived him. On December 28, 1844 d'Arrest discovered then another comet.
In 1845 he became assistant to Johann Franz Encke at the Berlin Observatory. Together with Johann Gottfried Galle discovered it on September 23, 1846 the planet Neptune. Galle and d'Arrest searched the sky systematically according to the instructions of the Frenchman Urbain Leverrier, who had calculated the position of the planets based on the perturbations of Uranus.
1848 d'Arrest moved to the observatory of the University of Leipzig in Pleissenburg. Here he started a systematic positioning of misty objects. In 1850 he was made an honorary Doctor of Philosophy Faculty of the University of Leipzig, 1851, he habilitated in here. On June 28, 1851, he discovered the periodic comet 6P / d'Arrest. In the same year he published a treatise on the orbits of minor planets. In the spring of 1852 he was a departure to Washington, DC to prevent, appointed associate professor of astronomy. D' Arrest initiated and promoted the construction of a new observatory at Leipzig Johannistal.
On November 4, 1851, he married in Leipzig, the daughter of August Ferdinand Möbius astronomer and mathematician, Auguste Emilie Möbius ( * October 19, 1822 in Leipzig, † December 28, 1897 in Copenhagen), with whom he one daughter ( Doris Sophie * March 5, 1853 ) and a son ( Louis, born March 31, 1855) had.
In September 1857 d'Arrest left Leipzig and worked as a professor of astronomy at the University of Copenhagen. With a telescope at the Copenhagen Observatory, which had an opening width of 27.5 cm, he continued his observation misty objects and discovered hundreds of galaxies, star clusters and nebulae. His observations he concluded in the 1867 published work siderum Nebulosorum Observationes Havnienses. On 21 October 1862 he discovered the asteroid (76 ) Freia with around 200 km in diameter.
Important for the professional world was his exploration of the Coma Cluster of galaxies, which he analyzed 1861-1867 by systematically scale observations. The Copenhagen telescope had an ideal for these purposes the visual field. About 30 years later, Max Wolf added that research in Heidelberg recorded by deep -reaching into the space photographs of the Coma cluster.
D' Arrest suffered in his last years strongly hypochondria. He died at the age of 52 of heart failure.
For his achievements, he received numerous awards and honors (1875 Gold Medal of the Royal Astronomical Society). He was a member of the Academy of Sciences of Denmark, Sweden, St. Petersburg and Munich, the British Royal Astronomical Society and the Knights of the Danish Dannebrog.
In his memory, the lunar crater D' Arrest, the crater D' Arrest on the Martian moon Phobos and the asteroid ( 9133 ) d'Arrest were named.