Johann Georg Hagen

Content sourced from Wikipedia, licensed under CC BY-SA 3.0.

Johann Georg Hagen (March 6, 1847 – September 6, 1930) was an Austrian Jesuit priest and astronomer. He studied mathematics and astronomy at the University of Bonn and the University of Münster, and joined the Jesuits in 1863 in Gorheim. He attended the Stella Matutina college in Feldkirch. He volunteered for the Franco-Prussian War’s ambulance service but contracted typhoid fever. After the Jesuits were expelled from Germany in 1872, he moved to England, where he was ordained, and in 1880 he moved to the United States. There he taught at Sacred Heart College in Prairie du Chien, Wisconsin, built a small observatory, and became a naturalized citizen.

In 1888 Hagen became Director of the Georgetown University Observatory. In 1906, Pope Pius X named him the first Jesuit director of the Vatican Observatory in Rome. He conducted important astronomical work and wrote several texts. The Rothe–Hagen identity in mathematics appears in his 1891 three-volume Synopsis of Higher Mathematics, and he contributed articles to the Catholic Encyclopedia.

Hagen was the spiritual director of Maria Elizabeth Hesselblad, whom he baptized in 1902; she was canonized in 2016. He died in Rome in 1930. The Moon crater Hagen (55 km in diameter) and the asteroid 562971 Johannhagen are named after him.