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),
thus galactic north has a positive declination.
A standardized galactic north position was defined as an element
of the galactic coordinate system (by the IAU in 1958), as perpendicular
to its standardized galactic plane, which was chosen as a reasonable
"nominal" 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 clearly deliberately rounded,
which I presume was because an actual axis is not precisely known and is
subject to technical definition, thus such a "north" sufficiently
precise for coordinates 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 changing the sign of the declination.
(Milky Way,coordinates,celestial sphere,astronomy)
Further reading:
https://en.wikipedia.org/wiki/Galactic_plane
https://en.wikipedia.org/wiki/Galactic_coordinate_system
https://cxc.cfa.harvard.edu/ciao/ahelp/prop-coords.html
https://ui.adsabs.harvard.edu/abs/1960MNRAS.121..123B/abstract
Coordinates: | galactic north B1249+2724 |
|
Referenced by pages:
2dF Galaxy Redshift Survey (2dFGRS)
galactic coordinate system (GCS)
galactic plane
Gould's Belt
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