The galactic plane is the plane on which the majority of a disk-shaped galaxy's mass lies. The directions perpendicular to the galactic plane point to the galactic poles. In actual usage, the terms galactic plane and galactic poles usually refer specifically to the plane and poles of the Milky Way, in which Planet Earth is located.
This edge-on view of the galaxy NGC 4452 from Earth shows its galactic plane, with the nucleus at the center.
This edge-on view of the spiral galaxyNGC 891 shows the profile of a dusty galactic plane.
Some galaxies are irregular and do not have any well-defined disk. Even in the case of a barred spiral galaxy like the Milky Way, defining the galactic plane is slightly imprecise and arbitrary since the stars are not perfectly coplanar. In 1959, the IAU defined the position of the Milky Way's north galactic pole as exactly RA = 12h 49m, Dec = 27° 24′ in the then-used B1950epoch;[citation needed] in the currently-used J2000 epoch, after precession is taken into account, its position is RA 12h 51m 26.282s, Dec 27° 07′ 42.01″.[citation needed] This position is in Coma Berenices, near the bright starArcturus; likewise, the south galactic pole lies in the constellationSculptor.
The "zero of longitude" of galactic coordinates was also defined in 1959 to be at position angle 123° from the north celestial pole. Thus the zero longitude point on the galactic equator was at 17h 42m 26.603s, −28° 55′ 00.445″ (B1950) or 17h 45m 37.224s, −28° 56′ 10.23″ (J2000), and its J2000 position angle is 122.932°. The Galactic Center is located at position angle 31.72° (B1950) or 31.40° (J2000) east of north.
Reid, M. J.; Brunthaler, A. (December 2004), "The Proper Motion of Sagittarius A*. II. The Mass of Sagittarius A*", The Astrophysical Journal, 616 (2): 872–884, arXiv:astro-ph/0408107, Bibcode:2004ApJ...616..872R, doi:10.1086/424960. See appendix for the numbers listed above.
May 11, 2023
galactic, plane, galactic, plane, plane, which, majority, disk, shaped, galaxy, mass, lies, directions, perpendicular, galactic, plane, point, galactic, poles, actual, usage, terms, galactic, plane, galactic, poles, usually, refer, specifically, plane, poles, . The galactic plane is the plane on which the majority of a disk shaped galaxy s mass lies The directions perpendicular to the galactic plane point to the galactic poles In actual usage the terms galactic plane and galactic poles usually refer specifically to the plane and poles of the Milky Way in which Planet Earth is located This edge on view of the galaxy NGC 4452 from Earth shows its galactic plane with the nucleus at the center This edge on view of the spiral galaxy NGC 891 shows the profile of a dusty galactic plane Some galaxies are irregular and do not have any well defined disk Even in the case of a barred spiral galaxy like the Milky Way defining the galactic plane is slightly imprecise and arbitrary since the stars are not perfectly coplanar In 1959 the IAU defined the position of the Milky Way s north galactic pole as exactly RA 12h 49m Dec 27 24 in the then used B1950 epoch citation needed in the currently used J2000 epoch after precession is taken into account its position is RA 12h 51m 26 282s Dec 27 07 42 01 citation needed This position is in Coma Berenices near the bright star Arcturus likewise the south galactic pole lies in the constellation Sculptor The zero of longitude of galactic coordinates was also defined in 1959 to be at position angle 123 from the north celestial pole Thus the zero longitude point on the galactic equator was at 17h 42m 26 603s 28 55 00 445 B1950 or 17h 45m 37 224s 28 56 10 23 J2000 and its J2000 position angle is 122 932 The Galactic Center is located at position angle 31 72 B1950 or 31 40 J2000 east of north See also EditGalactic coordinate system LHS 1815b example of outside galactic plane exoplanet Zone of AvoidanceExternal links EditReid M J Brunthaler A December 2004 The Proper Motion of Sagittarius A II The Mass of Sagittarius A The Astrophysical Journal 616 2 872 884 arXiv astro ph 0408107 Bibcode 2004ApJ 616 872R doi 10 1086 424960 See appendix for the numbers listed above Retrieved from https en wikipedia org w index php title Galactic plane amp oldid 1121264377, wikipedia, wiki, book, books, library,
