galactic equator

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galactic equator

A great circle on the celestial sphere. The galactic plane, which contains the galactic equator, is the plane that passes most nearly through the central plane of the spiral disk of our Galaxy. The galactic plane and celestial equator are inclined at an angle of about 63°. The nominal galactic center lies on the galactic equator in the direction of the constellation Sagittarius and is the zero point for the galactic coordinate system.

Galactic Equator


the great circle along which the plane of symmetry of the Milky Way System intersects the celestial sphere; the center line of the Milky Way coincides with the galactic equator. The galactic equator is perpendicular to the Milky Way System’s axis of rotation. Near the plane of the equator the galactic concentration of stars and interstellar matter reaches its maximum. In galactic space the sun is at a distance of only about 15 parsecs from the plane of the galactic equator and is on the northern side of it. The galactic equator serves as the principal great circle for the galactic system of celestial coordinates. The location of the galactic equator in stellar-astronomical research is often approximated, drawn where the greatest concentration of stars or other galactic objects is noted. In the galactic system of coordinates, however, the galactic equator is defined rigorously and uniquely by the precise position of its poles. The galactic equator forms an angle of 62.6° with the celestial equator. The north pole of the galactic equator lies in the constellation Coma Berenices, and the south pole in the constellation Sculptor.


Kurs astrofiziki i zvezdnoi astronomii, vol. 2. Moscow, 1962.


galactic equator

[gə′lak·tik i′kwād·ər]
A great circle of the celestial sphere, inclined 62° to the celestial equator, coinciding approximately with the center line of the Milky Way, and constituting the primary great circle for the galactic system of coordinates; it is everywhere 90° from the galactic poles. Also known as galactic circle.
References in periodicals archive ?
Thus when we look toward the winter Milky Way proper, along the galactic equator from Auriga to Puppis, we are in fact looking "over" Gould's Belt, which is a foreground structure within our Orion-Cygnus Arm.
But there are also clusters, associations, and nebulae at a wide range of distances right on the galactic equator.
The IC 1848/1805 complex is at about the same distance (7,500 light-years) as the Perseus Double Cluster, and the line joining the Double Cluster to the nebula complex is perpendicular to the galactic equator.
But it's just not the glow of stars that's concentrated in the equatorial disk and therefore near the line of the galactic equator in our sky.
Numerous compact radio sources along the galactic equator have the right characteristics to be young supernova remnants.
There are two other notable 4th-magnitude stars on the galactic equator in Vela: d Velorum and Phi ([phi]) Velorum.
He finds that the galactic equator (as defined by the International Astronomical Union in 1959) passed over the solstice points during May 1998.
One of its most spectacular features is a dense starcloud just east of the galactic equator in the tiny constellation Scutum.
The Milky Way band, broad and irregular as it is, straddles the thin line of the galactic equator.
These sights are actually easier to find with a telescope than most clusters and nebulae along the brightly lit galactic equator.
Adrift now in the rich-field shoals at the galactic equator, we pick our way slowly.
Galactic coordinates (galactic longitude and latitude) use the galactic equator, a line along the center of the Milky Way band, with the Milky Way's nucleus in Sagittarius as the zero point.