Jan H. OortDied 5 Nov 1992 at age 92 (born 28 Apr 1900).Jan Hendrik Oort was a Dutch physicist and astronomer, one of the most important figures in 20th-century efforts to understand the nature of the Milky Way Galaxy, who measured the rotation of the earth's galaxy and hypothesized an "Oort Cloud." In 1927 Oort analyzed motions of distant stars, found evidence for differential rotation and founded the mathematical theory of galactic structure. After World War II, he led the Dutch group which used the 21-cm line to map hydrogen gas in the Galaxy. They found the large-scale spiral structure, the galactic center, and gas cloud motions. In 1950 Oort proposed the now generally accepted model for the origin of comets. He continued researching galaxies until shortly before his death at 92. |
