10 articles for "Galactic"

The central region of our galaxy (Milky Way). It is located near to the point with zero Galactic Longitude and Latitude (l =0°, b= 0°).

See also: ♦ Galactic Coordinates ♦ Milky Way

The nucleus or center of our Galaxy. This iscurrently located in the vicinity of 27 Sagittarius.

See also: ♦ Galactic Coordinates ♦ Milky Way

The gravitational center around which the Sun revolves. Astrology has hypothetically placed this at 0° Capricorn, which is exactly confirmed by recently published results of thousands of calculations of spectroscopic radial velocity measurements, and other thousands by the parallax method of determining proper motion, by Charlier, Stromberg, Wilson, Campbell and More, and Smart and Green. In consequence the astronomers have arrived at a position of the center of the Milky Way Galaxy at R.A. 270°, declin. +29.7°. Therefore at the time of the Winter Solstice, the Galactic Center is a few degrees South of the Sun.

The Sun's actual travel is estimated at 200 miles per second in orbit. As it is placed about 30,000 light-years from the center of the Milky Way Galaxy, one complete orbit is estimated to require 200 million years. Its apparent motion toward a point near Wega in the constellation Hercules, as measured by nearby stars, is 12 miles per second — which should not be confused with its computed actual rate of travel.

The plane of the Sun's orbit is presumed to be approximately that of the Galactic Center, which is inclined to the Earth's orbit by about 50 degrees.

See also: ♦ Galactic Coordinates ♦ Milky Way

A great circle of the celestial sphere which passes through the nominal galactic center, and is inclined at an angle of about 62° to the celestial equator of 1950.0. The plane of the galactic circle, which defines the galactic circle, has been chosen so that it represents a mean path through the stars which comprise the Milky Way.

See also: ♦ Galactic Coordinates ♦ Great Circle ♦ Celestial Sphere ♦ Galactic Center ♦ Celestial Equator

A large proportion of galaxies occur in clusters, which are groups of galaxies containing a few thousand members. Our own galaxy is a member of a cluster of about two dozen galaxies known as the local group.

See also: ♦ Local Group of Galaxies

Coordinate system which uses the galactic circle as its fundamental circle and places its origin near the galactic center in the constellation Sagittarius. The coordinates are: galactic longitude (l) and galactic latitude (b). Galactic Longitude is measured eastward along the galactic circle (from 0° to 360°) from the nominal galactic center to the foot of a perpendicular circle passing through the body; Galactic Latitude is measured along this perpendicular circle, from the galactic equator to the body (+ is north, - is south). In 1959, the IAU (International Astronomical Union) set the nominal galactic center at: RA=17h42.4m, DEC=-28°55', referred to the mean equator and equinox of 1950.0, and defined the galactic equator to be inclined at an angle of about 62° to that same reference system. See Figure G1. Currently, the radio and infrared source known as Sagittarius A West is thought to coincide with the galactic center. This source is located only a few minutes of arc from the nominal center, at the galactic coordinates: l= -3.34', b= -2.75'.

See also: ♦ Coordinate System ♦ Galactic Circle ♦ Galactic Center ♦ Galactic Latitude

A co-ordinate system which structuresand defines a Galaxy, such as the Galaxy which contains our Sun. Once so divided then positions within the Galaxy can be determined. The Galactic Co-ordinate System allows one to introduce the concept of Sensitive Points within Galactic Co-ordinates as well as the Sensitive Points within the Horizon System.

See also: ♦ Coordinate System ♦ Galactic Circle ♦ Galactic Center ♦ Galactic Latitude

The angular distance of a celestial body from the median plane of the Milky Way.

See also: ♦ Galaxy ♦ Galactic Circle ♦ Galactic Center ♦ Galactic Plane ♦ Galactic Rotation ♦ Galactic Cluster ♦ Milky Way

The central part of a Galaxy. The central plane ofthe co-ordinate system which defines that Galaxy.

See also: ♦ Galaxy ♦ Galactic Circle ♦ Galactic Center ♦ Galactic Plane ♦ Galactic Rotation ♦ Galactic Cluster ♦ Milky Way

The rotation of a galaxy around a central point. For our own galaxy (the Milky Way), the galactic center lies in the direction of the constellation Sagittarius. Our galaxy exhibits differential rotation; that is, stars near the center complete a revolution faster than outlying ones. Our own star, the sun, makes one circle of the galactic center in about 225 million years.

See also: ♦ Galaxy ♦ Milky Way ♦ Galactic Center ♦ Sagittarius ♦ Galactic Rotation ♦ Differential Rotation