Aspects of this topic are discussed in the following places at Britannica.
in astronomy, galactic latitude or longitude. The two coordinates constitute a useful means of locating the relative positions and motions of components of the Milky Way Galaxy. Galactic latitude (denoted by the symbol b) is measured in degrees north or south of the Galaxy’s fundamental plane of symmetry. This plane is defined by the galactic equator, the great circle in the sky best...
...in a manner similar to the pattern for the planets of the solar system, which have nearly circular orbits around the Sun. Because the rotation rate is different at different distances from the centre of the Galaxy, the measured velocities of disk stars in different directions along the Milky Way exhibit different patterns. The Dutch astronomer Jan H. Oort first interpreted this effect in...
...of the Galaxy, nor are they found within the spiral arms. By these criteria, the planetaries reveal themselves to be rather middle-aged; they are moderately but not strongly concentrated in the plane; rather, they are concentrated toward the galactic centre, as the older objects are. Their motions in the Galaxy follow elliptical paths, whereas circular orbits are characteristic of younger...
American astronomer who deduced that the Sun lies near the central plane of the Galaxy some 30,000 light-years away from the centre.
in star cluster: General description and classification )...Galaxy. In 1917, from a study of the distances and distributions of globular clusters, the American astronomer Harlow Shapley, then of the Mount Wilson Observatory in California, determined that its galactic centre lies in the Sagittarius region. In 1930, from measurements of angular sizes and distribution of open clusters, Robert J. Trumpler of Lick Observatory in California, showed that light...
Link to this article and share the full text with the readers of your Web site or blog-post.
If you think a reference to this article on "galactic centre" will enhance your Web site,
blog-post, or any other web-content, then feel free to link to this article,
and your readers will gain full access to the full article, even if they do not subscribe to our service.
You may want to use the HTML code fragment provided below.
We welcome your comments. Any revisions or updates suggested for this article will be reviewed by our editorial staff. Contact us here.
Regular users of Britannica may notice that this comments feature is less robust than in the past. This is only temporary, while we make the transition to a dramatically new and richer site. The functionality of the system will be restored soon.