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Ursa Major Dwarf (other)
Ursa Major Dwarf is a name for two dwarf spheroidal galaxies orbiting the Milky Way Galaxy. * Ursa Major I Dwarf, also called UMa I dSph, was discovered in 2005. * Ursa Major II Dwarf, also called UMa I, dSph, was discovered in 2006. See also * Palomar 4 Palomar 4 is a globular cluster of the Milky Way galaxy belonging to the Palomar Globular Clusters group. It was discovered in 1949 by Edwin Hubble and again in 1955 by A. G. Wilson. Based on measurements of the stars from the Gaia spacecraft, ..., once thought to be a satellite galaxy, now known to be a globular cluster of the Milky Way {{SIA Ursa Major ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ursa Major I Dwarf
Ursa Major I Dwarf (UMa I dSph) is a dwarf spheroidal galaxy that satellite galaxy, orbits the Milky Way galaxy. It was discovered in 2005 within the Ursa Major constellation and is the third least luminous known galaxy. Discovery It was discovered by Beth Willman, Julianne Dalcanton, Julianne J. Dalcanton, David Martinez-Delgado, and Andrew A. West in 2005. Properties Being a small dwarf galaxy, it measures only a few thousand light-years in diameter. As of 2006, it is the third least luminous galaxy known (discounting possible dark galaxy, dark galaxies such as VIRGOHI21 in the Virgo cluster of galaxies), after the Boötes Dwarf (absolute magnitude −5.7) and the more recently discovered Ursa Major II Dwarf (absolute magnitude −3.8). The absolute magnitude of the galaxy is estimated to be only −6.75, meaning that it is less luminous than some stars, like Deneb in the Milky Way. It is comparable in luminosity to Rigel. It has been described as similar to the Sextans Dwarf Ga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ursa Major II Dwarf
Ursa Major II Dwarf (UMa II dSph) is a dwarf spheroidal galaxy situated in the Ursa Major constellation and discovered in 2006 in the data obtained by the Sloan Digital Sky Survey. The galaxy is located approximately 30 kpc from the Sun and moves towards the Sun with the velocity of about 116 km/s. It has an elliptical (ratio of axes ~ 2:1) shape with the Effective radius, half-light radius of about 140 pc. Ursa Major II is one of the smallest and faintest satellites of the Milky Way—its integrated luminosity is about 4000 times that of the Sun (absolute visible magnitude of about −4.2), which is much lower than the luminosity of the majority of globular clusters. UMa II is even less luminous than some stars, like Canopus in the Milky Way. It is comparable in luminosity to Bellatrix in Orion (constellation), Orion. However, its mass is about 5 million solar masses, which means that galaxy's mass to light ratio is around 2000. This may be an overestimate as the ga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palomar 4
Palomar 4 is a globular cluster of the Milky Way galaxy belonging to the Palomar Globular Clusters group. It was discovered in 1949 by Edwin Hubble and again in 1955 by A. G. Wilson. Based on measurements of the stars from the Gaia spacecraft, it is at least from the Sun. This star cluster is further away than the SagDEG satellite galaxy. Initially it was thought to be a dwarf galaxy A dwarf galaxy is a small galaxy composed of about 1000 up to several billion stars, as compared to the Milky Way's 200–400 billion stars. The Large Magellanic Cloud, which closely orbits the Milky Way and contains over 30 billion stars, is so ..., and it was given the name Ursa Major Dwarf. However, it was later discovered to be a globular cluster. See also * Ursa Major Dwarf References External links * * Palomar 04 Palomar 04 Palomar 04 Local Group UGCA objects {{star-cluster-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
