- Monoceros Ring
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The Monoceros Ring is a ring of stars around the Milky Way which is proposed to consist of a stellar stream torn from the Canis Major Dwarf Galaxy as it merges with the Milky Way over the course of billions of years. It is a complex ringlike structure which wraps around our galaxy three times, formed from the long filament of stars pulled from the Canis Major Dwarf Galaxy by tidal forces as it orbits the Milky Way. The ring has a mass of 100 million solar masses and is 200,000 light years long.[1]
The stream of stars was first reported in 2002 by astronomers conducting the Sloan Digital Sky Survey. It was in the course of investigating this ring of stars, and a closely spaced group of globular clusters similar to those associated with the Sagittarius Dwarf Elliptical Galaxy, that the Canis Major Dwarf Galaxy was discovered. In 2006, a study using 2MASS data cast doubts on the nature of the "Ring", arguing that the data is suggestive of the fact that the ring is actually part of the warped galactic disc of the Milky Way. However, observations using the Anglo-Australian Telescope published in 2007 suggest that a warped disc cannot create the observed structure, which must therefore be formed either by a flare of the Galactic disc or have an extra-Galactic origin.
References
- ^ Ibata, Rodrigo; Gibson, Brad (April 2007). "The Ghosts of Galaxies Past". Scientific American 296 (4): 40–45. doi:10.1038/scientificamerican0407-40. PMID 17479629.
External links
- Monoceros Ring at Space Wiki
- The Ghost of Sagittarius and Lumps in the Halo of the Milky Way Newberg H. J., et al., 2002, ApJ, 569, 245
- Deriving The Shape Of The Galactic Stellar Disc (SkyNightly) March 17, 2006
- Deriving the shape of the Galactic stellar disc, A&A press release, March 16, 2006
- Outer structure of the Galactic warp and flare: explaining the Canis Major over-density, Astronomy & Astrophysics, 2006
- The AAT/WFI survey of the Monoceros Ring and Canis Major Dwarf galaxy: I. from l = (193 - 276)°, Conn, Blair C., et al., 2007, MNRAS, in press
The Milky Way Location Milky Way subgroup → Local Group → Virgo Supercluster → Pisces-Cetus Supercluster Complex → Observable universe → Universe
Galactic core Spiral arms Satellite galaxies Sagittarius Stream · Boötes II · Coma Berenices · Messier 54 · Palomar 12 · Segue 1 · Segue 2 · Terzan 7Boötes I · Boötes III · Canes Venatici I · Canes Venatici II · Canis Major · Carina · Draco · Fornax · Hercules · Leo I · Leo II · Leo IV · Leo V · Phoenix · Pisces I · Pisces II · Sculptor · Sextans · Ursa Major I · Ursa Major II · Ursa MinorOtherCategories:- Milky Way Galaxy
- Canis Major Dwarf Galaxy
- Milky Way Subgroup
- Stellar streams
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