Astrophysics (Index)About

galactic north

(galactic north pole, north galactic pole)
(determination of the more northern direction of the Milky Way's axis)

Galactic north (the galactic north pole or north galactic pole) is the point on the celestial sphere in a direction parallel to the Milky Way's axis, specifically, in the direction closer to celestial north pole (northward along the Earth's axis), giving the point a positive declination. A galactic north position is standardized within the definition of the galactic coordinate system (by the IAU in 1958), as perpendicular to its standardized galactic plane, which was chosen as a reasonable determination of the plane in which the Milky Way's disk resides. The galactic north position was specified in B1950.0 coordinates as B124900+272400, which was deliberately rounded, I presume because it is somewhat arbitrary. Translated to epoch J2000.0, it is roughly right ascension 125126.28 and declination +270741.9. The other galactic pole (the south galactic pole) is in the opposite direction, i.e., subtracting 12 hours from the right ascension and negating the declination.

(Milky Way,coordinates,celestial sphere,astronomy)
Further reading:
Coordinates:galactic north

Referenced by page:
Gould's Belt