Christian Severin, “Longomontanus”

b. Longberg, Jutland, Denmark, 4 October 1562; d. Copenhagen, Denmark, 8 October 1647

            Christian Severin was the son of two peasants, Søren Poulsen and Maron Christensdatter.  After Severin’s father died, his mother could now afford for him to go to school continuously, in result, having Severin finish school when he was twenty six. After servicing Tycho Brahe until 1597, he received an MA at the University of Rostock. He then returned home and became a college professor in 1607, teaching science and mathematics at the University of Copenhagan. He remained there until his death in 1647. When Tycho died in 1601, his program for the restoration of astronomy was unfinished. Two tasks were left: the selection and integration of the data of the motions of the planets, and the presentation of the results of the entire program in the form of a treaty. Severin, Tycho’s closest, assumed the responsibility and fulfilled both tasks in his Astronomia danica in 1662. Although Severin worked and wrote in the era of Kepler and Galileo, he didn’t believe in ellipses, heliocentrism, the telescope, and logarithms. Regardless of his knowledge as an astronomist, Severin’s reputation suffered in comparison to Kepler’s achievements. Severin’s prestige attached to his work saw it through two reprintings despite the appearance of Kepler's Tabulae Rudolphinae in 1627. In Severin’s honor, there is a massive inpact crater named after him, Longomontanus, located southwest of Tycho, another crater.