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Robert's Quartet
Robert's Quartet is a compact galaxy group approximately 160 million light-years away in the constellation Phoenix. It is a family of four very different galaxies whose proximity to each other has caused the creation of about 200 star-forming regions and pulled out a stream of gas and dust 100,000 light years long. Its members are NGC 87, NGC 88, NGC 89 and NGC 92, discovered by John Herschel on the 30 September 1834. The quartet is one of the best examples of compact galaxy groups. Because such groups contain four to eight galaxies in a very small region they are excellent laboratories for the study of galactic interactions and their effects, in particular on the formation of stars. The quartet has a total visual magnitude of almost 13. The brightest member of the group is NGC 92, having the blue magnitude of 13.8. On the sky, the four galaxies are all within a circle of radius of 1.6 arcmin, corresponding to about 75,000 light-years. It was named by Halton Arp and Barry F. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barry F
Barry may refer to: People and fictional characters * Barry (name), including lists of people with the given name, nickname or surname, as well as fictional characters with the given name * Dancing Barry, stage name of Barry Richards (born c. 1950), former dancer at National Basketball Association games Places Canada *Barry Lake, Quebec *Barry Islands, Nunavut United Kingdom * Barry, Angus, Scotland, a village ** Barry Mill, a watermill * Barry, Vale of Glamorgan, Wales, a town ** Barry Island, a seaside resort ** Barry Railway Company ** Barry railway station United States * Barry, Illinois, a city * Barry, Minnesota, a city * Barry, Texas, a city * Barry County, Michigan * Barry County, Missouri * Barry Township (other), in several states * Fort Barry, Marin County, California, a former US Army installation Elsewhere * Barry Island (Debenham Islands), Antarctica * Barry, New South Wales, Australia, a village * Barry, Hautes-Pyrénées, France, a commune Arts and ent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copeland Septet
The Copeland Septet (also Copeland's Septet, Hickson Compact Group 57) is a group of galaxies in the constellation Leo that includes NGC 3748, NGC 3754, NGC 3750, NGC 3751, NGC 3745, NGC 3753 and NGC 3746. The group was discovered by British astronomer Ralph Copeland in 1874. The location of Copeland's Septet is right ascension / declination (2000.0), about three degrees northwest of third magnitude star 93 Leonis. See also * Wild's Triplet * Zwicky's Triplet * Robert's Quartet Robert's Quartet is a compact galaxy group approximately 160 million light-years away in the constellation Phoenix. It is a family of four very different galaxies whose proximity to each other has caused the creation of about 200 star-forming ... * Stephan's Quintet and NGC 7331 Group (also known as the ''Deer Lick Group'' located about half a degree northeast of Stephan's Quintet) * Seyfert's Sextet References Leo (constellation) 57 {{galaxy-cluster-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seyfert's Sextet
Seyfert's Sextet is a group of galaxies about 190 million light-years away in the constellation Serpens. The group appears to contain six members, but one of the galaxies, NGC 6027d, is a background object and another "galaxy," NGC 6027e, is actually a part of the tail from galaxy NGC 6027. The gravitational interaction among these galaxies should continue for hundreds of millions of years. Ultimately, the galaxies will merge to form a single giant elliptical galaxy. Discovery The group was discovered by Carl Keenan Seyfert using photographic plates made at the Barnard Observatory of Vanderbilt University. When these results were first published in 1951, this group was the most compact group ever identified. Members See also * Wild's Triplet * Zwicky's Triplet * Robert's Quartet * Stephan's Quintet and NGC 7331 Group ( Also known as the ''Deer Lick Group'', about half a degree northeast of Stephan's Quintet) * Copeland Septet The Copeland Septet (also Copeland' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 7331 Group
NGC 7331 Group is a visual grouping of galaxies in the constellation Pegasus. Spiral galaxy NGC 7331 is a foreground galaxy in the same field as the collection, which is also called the ''Deer Lick Group''. It contains four other members, affectionately referred to as the "fleas": the lenticular or unbarred spirals NGC 7335 and NGC 7336, the barred spiral galaxy NGC 7337 and the elliptical galaxy NGC 7340. These galaxies lie at distances of approximately 332, 365, 348 and 294 million light years, respectively. Although adjacent on the sky, this collection is not a galaxy group, as NGC 7331 itself is not gravitationally associated with the far more distant "fleas"; indeed, even they are separated by far more than the normal distances (~2 Mly) of a galaxy group. See also * Stephan's Quintet, another visual grouping that is not (purely) a galaxy group. Ironically, its non-group member, NGC 7320, might be a member of a true NGC 7331 group, having a similar redshift to that ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stephan's Quintet
Stephan's Quintet is a visual grouping of five galaxies of which four form the first compact galaxy group ever discovered. The group, visible in the constellation Pegasus, was discovered by Édouard Stephan in 1877 at the Marseille Observatory. The group is the most studied of all the compact galaxy groups. The brightest member of the visual grouping (and the only non-member of the true group) is NGC 7320, which has extensive H II regions, identified as red blobs, where active star formation is occurring. Four of the five galaxies in Stephan's Quintet form a physical association, a true galaxy group, Hickson Compact Group 92, and will likely merge with each other. Radio observations in the early 1970s revealed a filament of emission between the galaxies in the group. This same region is also detected in the faint glow of ionized atoms seen in the visible part of the spectrum as a green arc. Space telescopes have provided new insight into the nature of the filament, which is n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zwicky's Triplet
Zwicky's Triplet (Arp 103) is a group of three galaxies visible in the constellation Hercules. The other Zwicky's Triplet IC 3481 at 12h 32m, +11° 24' (2000.0) in Virgo, which is connected to PGC 41646 ("IC 3481A") as the system Arp 175, but probably not connected to IC 3483, is sometimes called Zwicky's Triplet, but this name is more often applied to the system at 16h 49m, +45° 30' (2000.0) in Hercules. See also * Wild's Triplet * Robert's Quartet * Stephan's Quintet * NGC 7331 Group (also known as the Deer Lick Group, about half a degree northeast of Stephan's Quintet) * Seyfert's Sextet * Copeland Septet The Copeland Septet (also Copeland's Septet, Hickson Compact Group 57) is a group of galaxies in the constellation Leo that includes NGC 3748, NGC 3754, NGC 3750, NGC 3751, NGC 3745, NGC 3753 and NGC 3746. The group was discovered by Britis ... References Hercules (constellation) Galaxy clusters {{galaxy-cluster-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wild's Triplet
Wild's Triplet is a group of three small, interacting spiral galaxies. The galaxies are visible in the constellation Virgo. The triplet has luminous connecting bridges and is located some 200 million light-years away. The aforementioned bridges are probably formed as a result of gravitational tidal interactions among the galaxies. The triplet is named after the British-born and Australia-based astronomer Paul Wild (1923–2008), who studied the trio in the early 1950s. See also * Zwicky's Triplet * Robert's Quartet * Stephan's Quintet * NGC 7331 Group (also known as the Deer Lick Group, about half a degree northeast of Stephan's Quintet) * Seyfert's Sextet * Copeland Septet The Copeland Septet (also Copeland's Septet, Hickson Compact Group 57) is a group of galaxies in the constellation Leo that includes NGC 3748, NGC 3754, NGC 3750, NGC 3751, NGC 3745, NGC 3753 and NGC 3746. The group was discovered by Britis ... References Virgo (constellation) {{galaxy-clu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apparent Magnitude
Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's light caused by interstellar dust along the line of sight to the observer. The word ''magnitude'' in astronomy, unless stated otherwise, usually refers to a celestial object's apparent magnitude. The magnitude scale dates back to the ancient Roman astronomer Claudius Ptolemy, whose star catalog listed stars from 1st magnitude (brightest) to 6th magnitude (dimmest). The modern scale was mathematically defined in a way to closely match this historical system. The scale is reverse logarithmic: the brighter an object is, the lower its magnitude number. A difference of 1.0 in magnitude corresponds to a brightness ratio of \sqrt /math>, or about 2.512. For example, a star of magnitude 2.0 is 2.512 times as bright as a star of magnitude 3.0, 6. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galaxy Morphological Classification
Galaxy morphological classification is a system used by astronomers to divide galaxies into groups based on their visual appearance. There are several schemes in use by which galaxies can be classified according to their morphologies, the most famous being the Hubble sequence, devised by Edwin Hubble and later expanded by Gérard de Vaucouleurs and Allan Sandage. However, galaxy classification and morphology are now largely done using computational methods and physical morphology. Hubble sequence The Hubble sequence is a morphological classification scheme for galaxies invented by Edwin Hubble in 1926. It is often known colloquially as the “Hubble tuning-fork” because of the shape in which it is traditionally represented. Hubble's scheme divides galaxies into three broad classes based on their visual appearance (originally on photographic plates): * Elliptical galaxies have smooth, featureless light distributions and appear as ellipses in images. They are denoted by the l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halton Arp
Halton Christian "Chip" Arp (March 21, 1927 – December 28, 2013) was an American astronomer. He was known for his 1966 ''Atlas of Peculiar Galaxies'', which (it was later theorized) catalogues many examples of interacting and merging galaxies, though Arp disputed the idea, claiming apparent associations were prime examples of ejections.Halton Arp, ''Seeing Red: Redshift, Cosmology and Academic Science'', Montreal: Aperion (1998), pp. 14, 61–62, 72, 104–105 Arp was also known as a critic of the Big Bang theory and for advocating a non-standard cosmology incorporating intrinsic redshift. Biography Arp was born on March 21, 1927, in New York City. He was married three times, has four daughters and five grandchildren. His bachelor's degree was awarded by Harvard (1949), and his PhD by Caltech (1953). Afterward he became a Fellow of the Carnegie Institution of Washington in 1953, performing research at the Mount Wilson Observatory and Palomar Observatory. Arp became a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
