The Orion Arm is a minor spiral arm of the Milky Way galaxy some 3,500 light-years (1,100 parsecs) across and approximately 10,000 light-years (3,100 parsecs) in length.[2] The Solar System and therefore the Earth lies within the Orion Arm. It is also referred to by its full name, the Orion–Cygnus Arm, as well as Local Arm, Orion Bridge, Local Spur and Orion Spur.
The Orion Arm is named for the Orion constellation, which is one of the most prominent constellations of Northern Hemisphere winter (Southern Hemisphere summer). Some of the brightest stars and most famous celestial objects of this constellation (Betelgeuse, Rigel, the stars of Orion's Belt, the Orion Nebula) are located within the Orion Arm, as shown on the interactive map below.
Our Local Arm is located between the Carina–Sagittarius Arm (toward the Galactic Center) and the Perseus Arm (toward the outside Universe), the latter one of the two major arms of the Milky Way. Within the Orion Arm, our Solar System and Earth are located close to the inner rim in the Local Bubble, about halfway along the Orion Arm's length, approximately 8,000 parsecs (26,000 light-years) from the Galactic Center.
Messier objects [edit]
The shape of the Orion Spur
[3]
The Orion arm contains a number of Messier objects:
Interactive maps [edit]
Orion and neighboring arms (clickable map)
The nearest nebulae and star clusters (clickable map)
See also [edit]
References [edit]
- ^ See the "Spiral Arms" part of this NASA animation for details
- ^ Harold Spencer Jones, T. H. Huxley, Proceedings of the Royal Institution of Great Britain, Royal Institution of Great Britain, v. 38–39
- ^ Vázquez, Ruben A.; May, Jorge; Carraro, Giovanni; Bronfman, Leonardo; Moitinho, André; Baume, Gustavo (January 2008). "Spiral Structure in the Outer Galactic Disk. I. The Third Galactic Quadrant". The Astrophysical Journal 672 (2): 930–939. arXiv:0709.3973. Bibcode:2008ApJ...672..930V. doi:10.1086/524003.
External links [edit]
