"Oort" redirects here. For other people with the surname, see Oort (surname). For Oort cloud, see Oort cloud.
Jan Oort
Jan Oort in May 1961
Born
(1900-04-28)28 April 1900
Franeker, Friesland
Died
5 November 1992(1992-11-05) (aged 92)
Leiden, South Holland
Nationality
Dutch
Known for
Oort cloud
Dark matter
Oort constants
Awards
Vetlesen Prize (1966) Kyoto Prize (1987)
Scientific career
Fields
Astronomy
Doctoral advisor
Jacobus Cornelius Kapteyn
A Dutch 1961 cinema newsreel showing the Leiden Observatory with domes, telescopes, history books and clocks. A densitometer. Professor Oort is explaining astronomical research and unanswered questions in Dutch.Oort with international astronomy colleagues on horseback reconnoitering the Chilean mountains for a location where to establish the European Southern Observatory, Cerro El Morado, Andes, Chile, June 1963.The single dish Dwingeloo Radio Observatory, the Netherlands, 2007.Westerbork Synthesis Radio Telescope, the Netherlands, 2007.
Jan Hendrik OortForMemRS[1] (/ˈɔːrt/ or /ˈʊərt/;[2] 28 April 1900 – 5 November 1992) was a Dutch astronomer who made significant contributions to the understanding of the Milky Way and who was a pioneer in the field of radio astronomy.[3]The New York Times called him "one of the century's foremost explorers of the universe";[4] the European Space Agency website describes him as "one of the greatest astronomers of the 20th century" and states that he "revolutionised astronomy through his ground-breaking discoveries."[5] In 1955, Oort's name appeared in Life magazine's list of the 100 most famous living people.[6] He has been described as "putting the Netherlands in the forefront of postwar astronomy."[4]
Oort determined that the Milky Way rotates and overturned the idea that the Sun was at its center. He also postulated the existence of the mysterious invisible dark matter in 1932, which is believed to make up roughly 84.5% of the total mass in the Universe and whose gravitational pull causes "the clustering of stars into galaxies and galaxies into connecting strings of galaxies".[4][7] He discovered the galactic halo, a group of stars orbiting the Milky Way but outside the main disk.[8] Additionally Oort is responsible for a number of important insights about comets, including the realization that their orbits "implied there was a lot more solar system than the region occupied by the planets."[4]
The Oort cloud, the Oort constants, and the asteroid 1691 Oort were all named after him.
^Van De Hulst, H. C. (1994). "Jan Hendrik Oort. 28 April 1900 – 5 November 1992". Biographical Memoirs of Fellows of the Royal Society. 40: 320–26. doi:10.1098/rsbm.1994.0042.
^"Oort". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
^Woltjer, Lodewijk (November 1993). "Obituary: Jan H. Oort". Physics Today. 46 (11): 104–05. Bibcode:1993PhT....46k.104W. doi:10.1063/1.2809110.
^ abcdWilford, John (12 November 1992). "Jan H. Oort, Dutch Astronomer In Forefront of Field, Dies at 92". New York Times. Retrieved 30 May 2014.
^"Jan Hendrik Oort: Comet Pioneer". European Space Agency. Retrieved 30 May 2014.
^Katgert-Merkelijn, J. (2000). "Jan Oort, astronomer : Catalogue of an exhibition in Leiden University library, April 20 - May 27, 2000". Jan Oort. Universiteitsbibliotheek Leiden. hdl:1887/77628.
^Bertschinger, Edmund. "Dark Matter Cosmological". Retrieved 30 May 2014.
^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): 256–60, Bibcode:1924PNAS...10..256O, doi:10.1073/pnas.10.6.256, PMC 1085635, PMID 16586938.
Jan Hendrik Oort ForMemRS (/ˈɔːrt/ or /ˈʊərt/; 28 April 1900 – 5 November 1992) was a Dutch astronomer who made significant contributions to the understanding...
cloud was proposed in 1950 by the Dutch astronomer JanOort, in whose honor the idea was named. Oort proposed that the bodies in this cloud replenish and...
Chandrasekhar revised the models of stellar dynamics first outlined by JanOort and others by considering the effects of fluctuating gravitational fields...
populations. In the abstract of the article by Baade, he recognizes that JanOort originally conceived this type of classification in 1926. Baade observed...
The Oort limit is a theoretical location at the outer limits of the Oort cloud, where the amount of comets and minor planets orbiting the Sun drops drastically...
The Oort constants (discovered by JanOort) A {\displaystyle A} and B {\displaystyle B} are empirically derived parameters that characterize the local...
cloud (also called the inner Oort cloud and inner cloud) is a theoretical vast circumstellar disc, interior to the Oort cloud, whose outer border would...
observed. Dutchman and radio astronomy pioneer JanOort also hypothesized the existence of dark matter in 1932. Oort was studying stellar motions in the local...
dynamics (MOND), which involves modifying the laws of gravity. In 1932, Jan Hendrik Oort became the first to report that measurements of the stars in the solar...
is the Oort cloud, possibly a spherical swarm of comets extending beyond 50,000 AU from the Sun first hypothesised by Dutch astronomer JanOort in 1950...
(The existence of two distinct populations had been noted earlier by JanOort.) Baade also discovered that there were two types of Cepheid variable stars...
(1920s), with some plausibility by 1939, and beyond reasonable doubt by JanOort in 1942. In 1921, Carl Otto Lampland was the first to announce that he...
1951. Using the radio telescope at the Kootwijk Observatory, Muller and Oort reported the detection of the hydrogen emission line in May of that same...
following year. He then commenced doctoral studies at Leiden University under JanOort. Schmidt was awarded a Doctor of Philosophy from Leiden Observatory in...
designed the receiver system. Because of his work with Dutch astronomer JanOort on the determination of the spiral structure of the Milky Way using the...
directed the observatory include Willem de Sitter, Ejnar Hertzsprung and JanOort. Leiden University established the observatory in 1633; astronomy had been...
ultimately led to the finding of galactic rotation by Bertil Lindblad and JanOort.[citation needed] In 1917, Heber Doust Curtis had observed the nova S Andromedae...
Dutch physicist, worked on Brownian motion and electrical noise theory JanOort (1900–1992) Dutch astronomer, pioneer in radio astronomy Hendrik Casimir...
activist (d. 1978) 1900 – Heinrich Müller, German SS officer (d. 1945) 1900 – JanOort, Dutch astronomer and academic (d. 1992) 1901 – H. B. Stallard, English...
the Galaxy. These discoveries were published in 1940 and were noted by JanOort who knew that significant advances could be made in astronomy if there...
astronomer JanOort. is a member of the Themis family, a dynamical family of outer-belt asteroids with nearly coplanar ecliptical orbits. Oort orbits the...
Jan van Oort (13 April 1921 – 29 November 2006) was a Dutch children's book writer and comic strip cartoonist, working under the pseudonym of Jean Dulieu...
Signals have travelled". Science Alert. Jan 20, 2021. Archived from the original on January 26, 2021. Retrieved Jan 20, 2021. Siemion, Andrew (September...
Frank J. Kerr John D. Kraus Bernard Lovell Christiaan Alexander Muller JanOort Joseph Lade Pawsey Ruby Payne-Scott Arno Penzias Grote Reber Martin Ryle...
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