Jan Oort

Jan Oort

Born 28 April 1900(1900-04-28)
Franeker, Friesland
Died 5 November 1992(1992-11-05) (aged 92)
Leiden
Nationality Dutch
Fields Astronomy
Doctoral advisor Jacobus Cornelius Kapteyn
Known for Oort cloud

Jan Hendrik Oort FRS[1] (Franeker, 28 April 1900 – Leiden, 5 November 1992) was a Dutch astronomer. He was a pioneer in the field of radio astronomy. The Oort cloud of comets bears his name.

Oort was born in Franeker, Friesland and studied in Groningen with Jacobus Cornelius Kapteyn. His Ph.D thesis was titled The stars of high velocity. In 1927 he confirmed Bertil Lindblad's theory that the Milky Way galaxy rotates, by analyzing the movements of stars.[2] In 1935 he became professor at the observatory of the University of Leiden, where Ejnar Hertzsprung was the director.

In 1928 his son Coen Oort was born, who later became an important Dutch economist and public official and who in 1990 headed the Oort Commission, which was responsible for a major overturn of Dutch tax law.

Oort was fascinated by radio waves from the universe. After the Second World War he began work in the new field of radio astronomy, using an old radar antenna from the Germans.

In the 1950s he raised funds for a new radio telescope in Dwingeloo, in the east part of the Netherlands, to research the center of the galaxy. In 1970 a bigger telescope (the Westerbork Synthesis Radio Telescope) was built in Westerbork, near the old one. It consisted of twelve smaller telescopes working together to perform radio interferometry observations, a technique which had been previously suggested by Oort, but which was first tested experimentally in Cambridge by Martin Ryle and in Sydney by Joseph Pawsey.

His hypothesis that the comets have a common origin, postulated in 1950, was later proven to be incorrect in detail, though correct in principle. That is, different types of comets have origins in different regions of the outer solar system. For more, see Oort Cloud, Hills Cloud, and Kuiper Belt. Another contribution Oort made was to demonstrate that the light from the Crab nebula was polarized.

Contents

A few of Oort's discoveries

Honors

Awards

Named after him

Upon his death, Nobel Prize Subrahmanyan Chandrasekhar remarked, "The great oak of Astronomy has been felled, and we are lost without its shadow."[4]

References

Notes

  1. ^ Van De Hulst, H. C. (1994). "Jan Hendrik Oort. 28 April 1900-5 November 1992". Biographical Memoirs of Fellows of the Royal Society 40: 320–326. doi:10.1098/rsbm.1994.0042.  edit
  2. ^ a b J. H. Oort (1927-04-14), "Observational evidence confirming Lindblad's hypothesis of a rotation of the galactic system", Bulletin of the Astronomical Institutes of the Netherlands 3 (120): 275–282, Bibcode 1927BAN.....3..275O. 
  3. ^ J. H. Oort; Arias, B; Rojo, M; Massa, M (June 1924), "On a Possible Relation between Globular Clusters and Stars of High Velocity", Proc Natl Acad Sci U S A. 10 (6): 256–260, Bibcode 1924PNAS...10..256O, doi:10.1073/pnas.10.6.256, PMC 1085635, PMID 16586938, http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1085635. 
  4. ^ van de Hulst, H. C. (1994), "Jan Hendrik Oort (1900–1992)", Quarterly Journal of the Royal Astronomical Society 35 (2): 237–242, Bibcode 1994QJRAS..35..237V. 

Literature

Online exhibition

Jan Oort, astronomer (Leiden University Library, April–May 2000) [1]

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