Since its founding in 1891, many people have passed through the doors of the Vatican Observatory. A quick perusal of our guestbook reveals several Names, including Popes, nobel laureates, astronauts, actors, and saints.
Today's guestbook entry is from April 24, 1908, when Elis Strömgren made a visit.
Next to his name, Svante Elis Strömgren (1870-1947) wrote, "Professor an der Universität, Kopenhagen" (Professor at the University of Copenhagen). He was a noteworthy astronomer who in 1907 became director of the Observatory of Copenhagen. His area of interest was primarily celestial mechanics, and he computed orbits for several comets. The asteroid (1422) Stromgrenia is named for him.
What makes him particularly notable, however, is not his own contribution but that of his children.
Bengt Strömgren (1908-1987) made several significant advances in astrophysics, including the measurement of elemental composition of stars: 70% hydrogen, 27% helium, and the remaining 3% everything else. I will write more about him in a future post, as he also signed our guestbook several decades later.
Erik Strömgren (1909-1993) was a notable psychiatrist who made several advances in bringing psychiatry up to the level of modern science. He introduced the concept of psychogenic psychosis. He also instituted a cross-sectional epidemiological survey of psychiatric patients in Denmark that has continued every 5 years since 1957. The Strömgren medal in psychiatry is awarded annually in his honor.