Jan Hendrik Oort

Dutch astronomer, pioneer in radio astronomy, comet and galaxy exploration. Oort showed that our sun is not at the centre of Universe, but just a star in the rotating Milky Way, one rotating galaxy between many others.

Jan Oort was the second child of the psychiatrist Abraham Hermanus Oort (28 March 1869, Harlingen - 12 May 1941, Leiden) and Ruth Hannah Faber (6 October 1869, Ossendrecht - 20 November 1957, Leiden), who married 14 September 1897 at Leiden and got five children. Both parents came from a family of pastors and theologians. The philologist, Orientalist and theologian Henricus Oort (27 December 1836, Eemnes - 13 December 1927, Leiden) was his grandfather.

When Oort was born his father worked in the psychiatric hospital of Franeker. At age 3, on 27 May 1903 his father got a job at the Rhijngeest Psychiatric Clinic in Oegstgeest. Here the family lived in the directors house of the clinic between the woods. Oort attended the primary school in Oegstgeest and the HBS in Leiden.

In 1917 he went to Groningen University, to study astronomy under the famous Jacobus Cornelius Kapteyn (19 Jan 1851, Barneveld - 18 June 1922, Amsterdam). He first doubted between physics and astronomy, but after his "Kandidaats" exam (2 July 1919) he got involved in the milky way research of Kapteyn. Kapteyn discovered in 1904 (in Leiden, as Groningen had not an astronomy observatory) the two main streams of stars that appear to be moving in opposite directions using spectroscopy and influenced both the empiricist Oort and the theorist Lindblad.

Jan Oort graduated 5 November 1921 cum laude. He worked here as an assistant of Kapteyns sucessor professor P.J. van Rhijn for a year and then studied from 1922 to 1924 at the observatory of the Yale University in Connecticut. He worked the positioning of start near to the sun, and had an interests in high velocity stars that did not fit the models.