The Canis Major Dwarf galaxy is located in the same part of the sky as the constellation of Canis Major. The galaxy contains a relatively high percentage of red giant stars, and is thought to contain an estimated one billion stars in all. The J2000. ... In astronomy, an epoch is a moment in time for which celestial coordinates or orbital elements are specified. ... This article does not cite any references or sources. ... Canis Major (IPA: , Latin: ) is one of the 88 modern constellations, and was also in Ptolemys list of 48 constellations. ... Equatorial Coordinates Right ascension (abbrev. ... In astronomy, declination (abbrev. ... Redshift of spectral lines in the optical spectrum of a supercluster of distant galaxies (right), as compared with that of the Sun (left). ... To help compare distances at different orders of magnitude this page lists lengths from 11,000 light years and 110,000 light years (1020 m and 1021 m). ... A light-year, symbol ly, is the distance light travels in one year: exactly 9. ... Astronomers classify galaxies based on their overall shape (elliptical, spiral or barred spiral) and further by the specific properties of the individual galaxy (for example degree of ellipse, number of spirals or definition of bar). ... The angular diameter of an object as seen from a given position is the diameter measured as an angle. ... This article describes the unit of angle. ... The apparent magnitude (m) of a star, planet or other celestial body is a measure of its apparent brightness as seen by an observer on Earth. ... NGC 4414, a typical spiral galaxy in the constellation Coma Berenices, is about 17,000 parsecs in diameter and approximately 20 million parsecs distant. ... List of galaxies: Abell 1835 IR1916 AM 0644-741 Andromeda Galaxy (M31/NGC 224) Andromeda I Andromeda II Andromeda III Aquarius Dwarf Barnards Galaxy (NGC 6822) Black Eye Galaxy (M64/NGC 4826) Bodes Galaxy (M81/NGC 3031) Canis Major Dwarf Galaxy Carina Dwarf Centaurus A Galaxy Draco Dwarf Fornax... This article does not cite any references or sources. ... Canis Major (IPA: , Latin: ) is one of the 88 modern constellations, and was also in Ptolemys list of 48 constellations. ... NGC 4414, a typical spiral galaxy in the constellation Coma Berenices, is about 17,000 parsecs in diameter and approximately 20 million parsecs distant. ... According to the Hertzsprung-Russell diagram, a red giant is a large non-main sequence star of stellar classification K or M; so-named because of the reddish appearance of the cooler giant stars. ... STAR is an acronym for: Organizations Society of Ticket Agents and Retailers], the self-regulatory body for the entertainment ticket industry in the UK. Society for Telescopy, Astronomy, and Radio, a non-profit New Jersey astronomy club. ... One thousand million (1,000,000,000) is the natural number following 999,999,999 and preceding 1,000,000,001. ...

The Canis Major dwarf galaxy is classified as an irregular galaxy and is now thought to be the closest neighbouring galaxy to our location in the Milky Way, being located about 25,000 light-years away from our Solar System and 42,000 light-years from the Galactic Center. It has a roughly elliptical shape and is thought to contain as many stars as the Sagittarius Dwarf Elliptical Galaxy, the previous contender for closest galaxy to our location in the Milky Way. A dwarf galaxy is a small galaxy composed of up to several billion stars, a small number compared to our own Milky Ways 200-400 billion stars. ... This article or section does not adequately cite its references or sources. ... The Milky Way as seen from Death Valley The Milky Way is the galaxy where the Solar System (and the Earth) is located. ... Major features of the Solar System (not to scale; from left to right): Pluto, Neptune, Uranus, Saturn, Jupiter, the asteroid belt, the Sun, Mercury, Venus, Earth and its Moon, and Mars. ... A light-year, symbol ly, is the distance light travels in one year: exactly 9. ... The Galactic Center is the rotational center of the Milky Way galaxy. ... The Sagittarius Dwarf Elliptical Galaxy (Sag DEG) is a satellite galaxy of the Milky Way Galaxy. ...

The galaxy was first discovered in November 2003 by an international team of French, Italian, British and Australian astronomers. Although closer to the Earth than the centre of the galaxy itself, the Canis Major Dwarf galaxy was difficult to detect as it is located behind the plane of the Milky Way, where concentrations of stars, gas and dust are densest. This, along with its small size, explains why it was not discovered sooner. An astronomer or astrophysicist is a person whose area of interest is astronomy or astrophysics. ... This article is about Earth as a planet. ...

The team of astronomers that discovered it were collaborating on analysis of data from the Two-Micron All Sky Survey, a comprehensive survey of the sky in infrared light, which is not blocked by gas and dust as severely as visible light. Because of this technique, scientists were able to detect a very significant over-density of class M giant stars in a part of the sky occupied by the Canis Major constellation, along with several other related structures composed of this type of star, two of which form broad, faint arcs. Observations for the Two Micron All-Sky Survey (2MASS) began in 1997 and were completed in 2001 at two telescopes located one each in the northern and southern hemispheres (Mt. ... Image of two girls in mid-infrared (thermal) light (false-color) Infrared (IR) radiation is electromagnetic radiation of a wavelength longer than that of visible light, but shorter than that of radio waves. ... In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral characteristics, and subsequently refined in terms of other characteristics. ...

Astronomers believe that the Canis Major Dwarf Galaxy is in the process of being pulled apart by the gravitational field of the more massive Milky Way galaxy. The main body of the galaxy is extremely degraded. Tidal disruption causes a long filament of stars to trail behind it as it orbits the Milky Way, forming a complex ringlike structure sometimes referred to as the Monoceros Ring which wraps around our galaxy three times. The stream of stars was first discovered in the early 21st century 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. The gravitational field is a field (physics), generated by massive objects, that determines the magnitude and direction of gravitation experienced by other massive objects. ... Comet Shoemaker-Levy 9 after breaking up under the influence of Jupiters tidal forces. ... Monoceros Ring is a proposed ring of stars around the Milky Way which consists of stars torn from the Canis Major Dwarf Galaxy as it merges with the Milky Way over the course of billions of years. ... SDSS Logo The Sloan Digital Sky Survey or SDSS is a major multi-filter imaging and spectroscopic redshift survey using a dedicated 2. ... A globular cluster is a spherical bundle of stars (star cluster) that orbits a galaxy as a satellite. ... The Sagittarius Dwarf Elliptical Galaxy (Sag DEG) is a satellite galaxy of the Milky Way Galaxy. ...

Globular clusters thought to be associated with the Canis Major Dwarf galaxy include NGC 1851, NGC 1904, NGC 2298 and NGC 2808, all of which are likely to be a remnant of the galaxy's globular cluster system before its accretion, or swallowing, into the Milky Way. NGC 1261 is another nearby cluster, but its velocity is different enough from that of the others to make its relation to the system unclear. The Canis Major Dwarf galaxy may also have associated open clusters, including Dol 25 and H18, and possibly AM2. It is thought that the open clusters may have formed due to the dwarf galaxy's gravity perturbing material in the galactic disk and stimulating star formation. NGC 1851 is a globular cluster located in the constellation Columba. ... Globular Cluster M79 (also known as Messier Object 79, Messier 79, M79, or NGC 1904) is a globular cluster in the Lepus constellation. ... NGC 2808 is a an globular cluster[1] in the constellation Carina. ... In astrophysics, the term accretion is used for at least two distinct processes. ... The Pleiades is one of the most famous open clusters. ... Sega AM2 is a research and development team for the video game company Sega. ... It has been proposed below that Disc (galaxy) be renamed and moved to galactic disc. ... Media:Example. ...

The discovery of the Canis Major Dwarf Galaxy and subsequent analysis of the stars associated with it has provided some support for the current theory that galaxies may grow in size by swallowing their smaller neighbors. Martin et al. believe that the preponderance of evidence points to the accretion of a small satellite galaxy of the Milky Way which was orbiting roughly in the plane of the galactic disk. A satellite galaxy orbits a larger galaxy, due to gravitational attraction. ... It has been proposed below that Disc (galaxy) be renamed and moved to galactic disc. ...

A new study by Yazan Momany using 2MASS data casts doubts on the nature of the dwarf galaxy. The data suggest that the Canis Major overdensity is actually part of the warped galactic disc. This conclusion, however, is still being challenged and the true nature of the overdensity in Canis Major remains unknown.^{[citation needed]} Observations for the Two Micron All-Sky Survey (2MASS) began in 1997 and were completed in 2001 at two telescopes located one each in the northern and southern hemispheres (Mt. ... Canis Major (IPA: , Latin: ) is one of the 88 modern constellations, and was also in Ptolemys list of 48 constellations. ...

See also

• Messier 79
• Omega Centauri
• Galaxy formation and evolution

Globular Cluster M79 (also known as Messier Object 79, Messier 79, M79, or NGC 1904) is a globular cluster in the Lepus constellation. ... A small region at the heart of Omega Centauri, containing some 50,000 stars (NASA/STScI) Omega Centauri or NGC 5139 is a globular cluster of stars orbiting our galaxy, the Milky Way. ... In astrophysics, the questions of galaxy formation and evolution are: How, from a homogeneous universe, did we obtain the very heterogeneous one we live in? How did galaxies form? How do galaxies change over time? A spectacular head-on collision between two galaxies is seen in this NASA Hubble Space...

External links

• Deriving The Shape Of The Galactic Stellar Disc (SkyNightly) Mar 17, 2006

References

• N. F. Martin, R. A. Ibata, M. Bellazzini, M. J. Irwin, G. F. Lewis, W. Dehnen, (February 2004). A dwarf galaxy remnant in Canis Major: the fossil of an in-plane accretion onto the Milky Way. Monthly Notices of the Royal Astronomical Society 348 (1) 12.
• Official press release announcing discovery (University of Strasbourg)
• SEDS page on the Canis Major dwarf galaxy

v • d • e The Milky Way

Galactic Core: Center of the Milky Way Spiral Arms: Sagittarius-Carina Arm • Scutum-Crux Arm • Norma-Cygnus Arm • Perseus Arm • Orion Arm Location: Universe • Virgo Supercluster • Local Group Satellite galaxies: Boötes Dwarf • Canes Venatici Dwarf • Canis Major Dwarf Galaxy • Carina Dwarf • Draco Dwarf • Fornax Dwarf • Large Magellanic Cloud • Leo I • Leo II • Sag DEG • Sculptor Dwarf Galaxy • Sextans Dwarf • Small Magellanic Cloud • Ursa Major Dwarf • Ursa Minor Dwarf • Virgo Stellar Stream Year 2007 (MMVII) is now the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era. ... March 16 is the 75th day of the year (76th in leap years) in the Gregorian calendar. ... The Milky Way as seen from Death Valley The Milky Way is the galaxy where the Solar System (and the Earth) is located. ... Image File history File links Download high resolution version (1350x1350, 954 KB)Barred Spiral Milky Way Illustration Credit: R. Hurt (SSC), JPL-Caltech, NASA From http://apod. ... The Galactic Center is the rotational center of the Milky Way galaxy. ... The Sagittarius Arm or Sagittarius-Carina Arm (labeled -I) is one of two major spiral arms of the Milky Way galaxy, along with the Cygnus Arm. ... The Scutum-Crux Arm or Centaurus Arm is a spiral arm of the Milky Way galaxy. ... Diagram of the Milky Ways spiral arms. ... The Perseus Arm (labeled +I) is a spiral arm of the Milky Way galaxy with a radius of 10. ... Observed structure of the Milky Ways spiral arms The Orion Arm or Local Arm (labeled 0) is a minor, spiral arm of the Milky Way galaxy. ... The Universe is defined as the summation of all particles and energy that exist and the space-time in which all events occur. ... The Virgo Supercluster The Virgo Supercluster or Local Supercluster is the galactic supercluster that contains the Local Group, the latter which, in its turn, contains the Milky Way and Andromeda galaxies. ... A member of the Local Group of galaxies, irregular galaxy Sextans A is 4. ... Category: ... The Boötes Dwarf Galaxy (Boo dSph) is the faintest galaxy yet discovered, as of 2006, with a total luminosity of 100,000 Suns, and an absolute magnitude of -5. ... The Canes Venatici Dwarf Galaxy (CVn dSph) is the most distant satellite galaxy of the Milky Way as of 2006. ... The Carina Dwarf is a dwarf galaxy in the Carina constellation. ... The Draco Dwarf galaxy was discovered by Albert G. Wilson of Lowell Observatory in 1954. ... The Fornax Dwarf is a dwarf galaxy in the constellation Fornax that was discovered in 1938 by Harlow Shapley. ... The Large Magellanic Cloud (LMC for short) is a dwarf galaxy that orbits our own galaxy, the Milky Way. ... Leo I is a dwarf spheroidal galaxy in the constellation Leo. ... Leo II (or Leo B) is an dwarf spheroidal galaxy of the Local Group, in the constellation of Leo. ... The Sagittarius Dwarf Elliptical Galaxy (Sag DEG) is a satellite galaxy of the Milky Way Galaxy. ... for SDIG, see Sculptor Dwarf Irregular Galaxy The Sculptor Dwarf Galaxy (also called E351-G30, PGC 3589, A0058, Sculptor Dwarf Spheroidal Galaxy) is a dwarf spheroidal galaxy in the Local Group that is a satellite of the Milky Way in the direction of the constellation of Sculptor. ... It has been suggested that this article or section be merged with Sextans A. (Discuss) The Sextans Dwarf Spheroidal is a dwarf spheroidal galaxy that was discovered in 1990 by Mike Irwin, M.T. Bridgeland, P.S. Bunclark and R.G. McMahon as the 8th satellite of the Milky Way... The Small Magellanic Cloud (SMC) is a dwarf galaxy[1] in orbit around the Milky Way Galaxy. ... Ursa Major Dwarf is a dwarf spheroidal galaxy orbiting the Milky Way galaxy. ... The Ursa Minor Dwarf dwarf galaxy was discovered by A.G. Wilson of the Lowell Observatory in 1954. ... The Virgo Stellar Stream (or Virgo Overdensity) is the proposed name for a stream of stars in the constellation of Virgo which was discovered in 2005. ...