what else has he discovered?
He showed that stars lying in the outer regions of the galactic disk rotated more slowly than those nearer the center. The Galaxy does not therefore rotate as a uniform whole but exhibits what is known as 'differential rotation'."
Jan Oort
He also showed that stars lying in the outer regions of the galactic disk rotated more slowly than those nearer the center. The Galaxy does not therefore rotate as a uniform whole but exhibits what is known as 'differential rotation'."
which describes a possible origin for the oort cloud The Oort cloud is thought to have developed after the formation of planets from the primordial protoplanetary disc approximately 4.6 billion years ago. what is it composed of? The vast majority of Oort-cloud objects consist of ices such as water, methane, ethane, carbon monoxide and hydrogen cyanide. who discovered it? Jan Oort who was he? He 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. where did he study? Groningen University
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Jan Oort [SEP] Early discoveries
He also showed that stars lying in the outer regions of the galactic disk rotated more slowly than those nearer the center. The Galaxy does not therefore rotate as a uniform whole but exhibits what is known as 'differential rotation'." These early discoveries by Oort about the Milky Way overthrew the Kapteyn system, named after his mentor, which had envisioned a galaxy that was symmetrical around the Sun. As Oort later noted, "Kapteyn and his co-workers had not realized that the absorption in the galactic plane was as bad as it turned out to be." Until Oort began his work, he later recalled, "the Leiden Observatory had been concentrating entirely on positional astronomy, meridian circle work and some proper motion work.