|
Andromeda Subgroup
The Andromeda Galaxy (M31) has satellite galaxies just like the Milky Way. Orbiting M31 are at least 13 dwarf galaxies: the brightest and largest is M110, which can be seen with a basic telescope. The second-brightest and closest one to M31 is M32. The other galaxies are fainter, and were mostly discovered only starting from the 1970s. On January 11, 2006, it was announced that Andromeda Galaxy's faint companion galaxies lie on or close to a single plane running through the Andromeda Galaxy's center. This unexpected distribution is not obviously understood in the context of current models for galaxy formation. The plane of satellite galaxies points toward a nearby group of galaxies (M81 Group), possibly tracing the large-scale distribution of dark matter. It is unknown whether the Triangulum Galaxy is a satellite of Andromeda. Table of known satellites Andromeda Galaxy's satellites are listed here by discovery (orbital distance is not known). Andromeda IV is not included in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 185
NGC 185 (also known as Caldwell 18) is a dwarf spheroidal galaxy located 2.08 million light-years from Earth, appearing in the constellation Cassiopeia. It is a member of the Local Group, and is a satellite of the Andromeda Galaxy (M31). NGC 185 was discovered by William Herschel on November 30, 1787, and he cataloged it "H II.707". John Herschel observed the object again in 1833 when he cataloged it as "h 35", and then in 1864 when he cataloged it as "GC 90" within his ''General Catalogue of Nebulae and Clusters''. NGC 185 was first photographed between 1898 and 1900 by James Edward Keeler with the Crossley Reflector of Lick Observatory. Unlike most dwarf elliptical galaxies, NGC 185 contains young stellar clusters, and star formation proceeded at a low rate until the recent past. NGC 185 has an active galactic nucleus (AGN) and is usually classified as a type 2 Seyfert galaxy, though its status as a Seyfert is questioned. It is possibly the closest Seyfert galaxy to Earth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andromeda XI
Andromeda XI (And 11) is a dwarf spheroidal galaxy about 2.6 million light-years away from the Sun in the constellation Andromeda. Discovered in 2006, And XI is a satellite galaxy of the Andromeda Galaxy The Andromeda Galaxy (IPA: ), also known as Messier 31, M31, or NGC 224 and originally the Andromeda Nebula, is a barred spiral galaxy with the diameter of about approximately from Earth and the nearest large galaxy to the Milky Way. The gala ... (M31). See also * List of Andromeda's satellite galaxies References {{DEFAULTSORT:Andromeda XI Andromeda (constellation) Dwarf spheroidal galaxies Astronomical objects discovered in 2006 Andromeda Subgroup Local Group ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andromeda X
Andromeda X (And 10) is a dwarf spheroidal galaxy about 2.9 million light-years away from the Sun in the constellation Andromeda. Discovered in 2005 by Zucker et al., And X is a satellite galaxy of the Andromeda Galaxy (M31). Aided by the application of stellar photometry to data from the Sloan Digital Sky Survey similar to the Andromeda IX discovery, the new finding indicates that this type of extremely faint satellite might be common in the Lower Group, potentially providing further support for hierarchical cold dark matter In cosmology and physics, cold dark matter (CDM) is a hypothetical type of dark matter. According to the current standard model of cosmology, Lambda-CDM model, approximately 27% of the universe is dark matter and 68% is dark energy, with only a sm ... models. See also * List of Andromeda's satellite galaxies References External links SEDS webpage for Andromeda X Dwarf spheroidal galaxies 5056921 Local Group Andromeda Subgroup Andromeda (c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andromeda IX
Andromeda IX (And 9) is a dwarf spheroidal satellite of the Andromeda Galaxy The Andromeda Galaxy (IPA: ), also known as Messier 31, M31, or NGC 224 and originally the Andromeda Nebula, is a barred spiral galaxy with the diameter of about approximately from Earth and the nearest large galaxy to the Milky Way. The gala .... It was discovered in 2004 by resolved stellar photometry from the Sloan Digital Sky Survey (SDSS), by Zucker et al. (2004). At the time of its discovery, it was the galaxy with the lowest known surface brightness, Σ''V'' ≃ 26.8mags arcsec−2 and the faintest galaxy known from its intrinsic absolute brightness. It was found from data acquired within an SDSS scan along the major axis of M31, on October 5, 2002. Its distance was estimated to be almost exactly the same as that of M31 by McConnacrchie et al. (2005). See also * List of Andromeda's satellite galaxies References External linksSEDS webpage for Andromeda IX {{DEFAULTSORT:Andromeda 09 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andromeda VIII
Andromeda VIII (And VIII / 8) is a galaxy discovered in August 2003. It is a companion galaxy to the Andromeda Galaxy, M31, and evaded detection for so long due to its diffuse nature. The galaxy was finally discovered by measuring the redshifts of stars in front of Andromeda, which proved to have different velocities Velocity is the directional speed of an object in motion as an indication of its rate of change in position as observed from a particular frame of reference and as measured by a particular standard of time (e.g. northbound). Velocity is a ... than M31 and hence were part of a different galaxy. As of at least 2006, the actuality of And VIII as a galaxy has not yet been firmly established (Merrett et al. 2006). See also * List of Andromeda's satellite galaxies References External linksSEDS Webpage for Andromeda VIII {{DEFAULTSORT:Andromeda 08 Andromeda Subgroup Local Group Andromeda (constellation) Dwarf spheroidal galaxies 5056928 Astronom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cassiopeia Dwarf
The Cassiopeia Dwarf (also known as Andromeda VII) is a dwarf spheroidal galaxy about 2.45 Mly away in the constellation Cassiopeia. The Cassiopeia Dwarf is part of the Local Group and a satellite galaxy of the Andromeda Galaxy (M31). In the sky, it appears behind the Milky Way's galactic plane, and so it is reddened by 0.194 magnitudes. With a luminosity of and a stellar mass of , it is the brightest and most massive of the Andromeda Galaxy's dwarf spheroidal galaxy satellites. It also has the highest metallicity out of all of them. The Cassiopeia Dwarf was found in 1998, together with the Pegasus Dwarf, by a team of astronomers (Karachentsev and Karachentseva) in Russia and Ukraine Ukraine ( uk, Україна, Ukraïna, ) is a country in Eastern Europe. It is the second-largest European country after Russia, which it borders to the east and northeast. Ukraine covers approximately . Prior to the ongoing Russian inv .... The Cassiopeia Dwarf and the Pegasus Dwa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pegasus Dwarf Spheroidal Galaxy
The Pegasus Dwarf Spheroidal (also known as ''Andromeda VI'' or ''Peg dSph'' for short) is a dwarf spheroidal galaxy about 2.7 million light-years away in the constellation Pegasus. The Pegasus Dwarf is a member of the Local Group and a satellite galaxy of the Andromeda Galaxy (M31). General information The Pegasus Dwarf Spheroidal is a galaxy with mainly metal-poor stellar populations. Its metallicity is e/H≃ −1.3. It is located at the right ascension 23h51m46.30s and declination +24d34m57.0s in the equatorial coordinate system (epoch J2000.0), and in a distance of 820 ± 20 kpc from Earth and a distance of 294 ± 8 kpc from the Andromeda Galaxy. The galaxy was discovered in 1999 by various authors on the Second Palomar Observatory Sky Survey (POSS II) films. See also * List of Andromeda's satellite galaxies * Pegasus Dwarf Irregular Galaxy (Peg DIG) * Pegasus galaxy, the Stargate Atlantis ''Stargate Atlantis'' (usually stylized in all caps and often abbrev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andromeda V
Andromeda V is a dwarf spheroidal galaxy about 2.52 Mly away in the constellation Andromeda. Andromeda V was discovered by Armandroff et al. and published in 1998 after their analysis of the digitized version of the second Palomar Sky Survey. The metallicity of Andromeda V is above the average metallicity to luminosity ratio of the Local Group The Local Group is the galaxy group that includes the Milky Way. It has a total diameter of roughly , and a total mass of the order of . It consists of two collections of galaxies in a "dumbbell" shape: the Milky Way and its satellites form ...'s dwarf galaxies. See also * List of Andromeda's satellite galaxies References External links SEDS: Dwarf Spheroidal Galaxy Andromeda VSIMBAD: And V -- Galaxy {{DEFAULTSORT:Andromeda 05 Dwarf spheroidal galaxies 3097824 Local Group Andromeda Subgroup Andromeda (constellation) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Irregular Galaxy
An irregular galaxy is a galaxy that does not have a distinct regular shape, unlike a spiral or an elliptical galaxy. Irregular galaxies do not fall into any of the regular classes of the Hubble sequence, and they are often chaotic in appearance, with neither a nuclear bulge nor any trace of spiral arm structure. Collectively they are thought to make up about a quarter of all galaxies. Some irregular galaxies were once spiral or elliptical galaxies but were deformed by an uneven external gravitational force. Irregular galaxies may contain abundant amounts of gas and dust. This is not necessarily true for dwarf irregulars. Irregular galaxies are commonly small, about one tenth the mass of the Milky Way galaxy. Due to their small sizes, they are prone to environmental effects like crashing with large galaxies and intergalactic clouds. Types There are three major types of irregular galaxies: * An Irr-I galaxy (Irr I) is an irregular galaxy that features some structure but not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andromeda III
Andromeda III is a dwarf spheroidal galaxy about 2.44 million light-years away in the constellation Andromeda. It is part of the Local Group and is a satellite galaxy of the Andromeda Galaxy (M31). The galaxy was discovered by Sidney van den Bergh on photographic plates taken in 1970 and 1971. Observations of the dwarf galaxy using the WFPC2 in 2002 indicate that the bulk of the galaxy is around three billion years younger than the general population of globular clusters in our own galaxy. However, there are some older stars that are comparable in age to the Milky Way galactic clusters. There is no evidence for younger stars in this dwarf galaxy, suggesting no star formation is occurring. The dwarf galaxy is located at a distance of around from the center of M31. A total of 56 variable stars have been discovered in And III, including 51 RR Lyrae variables. See also * List of Andromeda's satellite galaxies The Andromeda Galaxy (M31) has satellite galaxies just like the Milky ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andromeda II
Andromeda II (And II) is a dwarf spheroidal galaxy about 2.22 light-year, Mly away in the constellation Pisces (constellation), Pisces. While part of the Local Group, it is not quite clear if it is a satellite of the Andromeda Galaxy or the Triangulum Galaxy. It was discovered by Sidney Van den Bergh in a survey of photographic plates taken with the Palomar 48-inch (1.2 m) Schmidt telescope in 1970 and 1971, together with Andromeda I, Andromeda III, and the presumable non- or background galaxy Andromeda IV. Nomenclature Andromeda II has also been given the alias Pisces II (dwarf galaxy), Pisces II by Martin et al. (2009), who also proposed aliases for several other satellite galaxies of the Andromeda Galaxy However, that name was later used by a different group unaware of these names, for a separate galaxy. Spectra observations Using the Keck telescope, Côté et al. 1999 observed Electromagnetic spectrum, spectra for seven stars inside Andromeda II. From this data, they f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |