Astronomer Biography: Christian Sorensen Longomontanus

Christen Sørensen Longomontanus, also known as Christen Severin, was born in Longberg, Denmark in 1562. He was born into a poor family and when his father died, his education was continually interrupted. Longomontanus eventually ran away to Viborg to finish schooling. In 1590, Longomontanus began working as Tycho Brahe's primary assistant at his observatory, Uraniborg.  After eight years of work with Brahe, Longomontanus left the island observatory to further study at various German universities. Later, in 1600, he joined Brahe again to complete work on Brahe's Lunar Theory. It is difficult to delineate what work was Brahe's and whose was Longomontanus' because they worked together so closely. Johannes Kepler, another of Brahe's more well-known assistants, eventually took on most of the research after Brahe's death. Longomontanus rejected most of Kepler's theories and left the observatory. Longomontanus went on to get a masters degree at Rostock and was employed by the chancellor of Denmark. He was elected to rector of the Viborg and later became a professor at the University of Copehnagen. He eventually became chair of mathematics there and held that position until his death in 1647.

Longomontanus is not a necessarily celebrated astronomer because of the lack of documentation of his research, it is agreed that he helped promote a lot of Brahe's theories. He helped synthesize data on the motion of planets that ultimately completed Brahe's work, with more contribution from Kepler. While Lognomontanus was not an extremely revolutionary thinker, Brahe might not have had such success without his aid.