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NGC 1387
NGC 1387 is a lenticular galaxy in the constellation Fornax, in the Fornax Cluster. It was discovered by William Herschel on December 25, 1835. At a distance of 53 million light-years, it is one of the closer members of the Fornax Cluster. It has a magnitude of 10.8, which makes NGC 1387 one of the brighter galaxies in the Fornax Cluster and it is 60 000 light-years across. It is only 12 arcminutes from the central galaxy NGC 1399, which makes it one of the closest galaxies to NGC 1399. NGC 1387 is an early-type galaxy with a Hubble classification of (R')SAB(s)0. It has a clear, normal-looking non-ansae type bar embedded in a very extensive envelope, which is structureless except for the bar. Observations in 2006 discovered a large nuclear ring around NGC 1387, in a bulge-subtracted 2.2 micron image. Despite their name, early-type galaxies are much older than spiral galaxies, and mostly comprise old, red-colored stars. Very little star formation occurs in these galaxies; the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New General Catalogue
The ''New General Catalogue of Nebulae and Clusters of Stars'' (abbreviated NGC) is an astronomical catalogue of deep-sky objects compiled by John Louis Emil Dreyer in 1888. The NGC contains 7,840 objects, including galaxies, star clusters and emission nebulae. Dreyer published two supplements to the NGC in 1895 and 1908, known as the ''Index Catalogues'' (abbreviated IC), describing a further 5,386 astronomical objects. Thousands of these objects are best known by their NGC or IC numbers, which remain in widespread use. The NGC expanded and consolidated the cataloguing work of William and Caroline Herschel, and John Herschel's ''General Catalogue of Nebulae and Clusters of Stars''. Objects south of the celestial equator are catalogued somewhat less thoroughly, but many were included based on observation by John Herschel or James Dunlop. The NGC contained multiple errors, but attempts to eliminate them were made by the ''Revised New General Catalogue'' (RNGC) by Jack W. Sulent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 1399
NGC 1399 is a large elliptical galaxy in the Southern constellation Fornax (constellation), Fornax, the central galaxy in the Fornax Cluster. The galaxy is 66 million light-years away from Earth. With a diameter of 130 000 light-years, it is one of the largest galaxies in the Fornax Cluster and slightly larger than the Milky Way. William Herschel discovered this galaxy on October 22, 1835. Characteristics It is a type-cD galaxy, with a bright center and a vast, diffuse envelope surrounding it. It is also an early-type galaxy, the largest one in the Fornax Cluster. Despite their name, early-type galaxies are much older than spiral galaxies, and mostly comprise old, red-colored stars. Very little star formation occurs in these galaxies; the lack of star formation in elliptical galaxies appears to start at the center and then slowly propagates outward. Globular clusters NGC 1399 is very rich in globular clusters. The population is estimated to be between 5700 and 6500. It h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC Objects
The ''New General Catalogue of Nebulae and Clusters of Stars'' (abbreviated NGC) is an astronomical catalogue of deep-sky objects compiled by John Louis Emil Dreyer in 1888. The NGC contains 7,840 objects, including galaxies, star clusters and emission nebulae. Dreyer published two supplements to the NGC in 1895 and 1908, known as the ''Index Catalogues'' (abbreviated IC), describing a further 5,386 astronomical objects. Thousands of these objects are best known by their NGC or IC numbers, which remain in widespread use. The NGC expanded and consolidated the cataloguing work of William and Caroline Herschel, and John Herschel's ''General Catalogue of Nebulae and Clusters of Stars''. Objects south of the celestial equator are catalogued somewhat less thoroughly, but many were included based on observation by John Herschel or James Dunlop. The NGC contained multiple errors, but attempts to eliminate them were made by the ''Revised New General Catalogue'' (RNGC) by Jack W. Sulenti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lenticular Galaxies
A lenticular galaxy (denoted S0) is a type of galaxy intermediate between an elliptical (denoted E) and a spiral galaxy in galaxy morphological classification schemes. It contains a large-scale disc but does not have large-scale spiral arms. Lenticular galaxies are disc galaxies that have used up or lost most of their interstellar matter and therefore have very little ongoing star formation. They may, however, retain significant dust in their disks. As a result, they consist mainly of aging stars (like elliptical galaxies). Despite the morphological differences, lenticular and elliptical galaxies share common properties like spectral features and scaling relations. Both can be considered early-type galaxies that are passively evolving, at least in the local part of the Universe. Connecting the E galaxies with the S0 galaxies are the ES galaxies with intermediate-scale discs. Morphology and structure Classification Lenticular galaxies are unique in that they have a visibl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elliptical Galaxies
An elliptical galaxy is a type of galaxy with an approximately ellipsoidal shape and a smooth, nearly featureless image. They are one of the four main classes of galaxy described by Edwin Hubble in his Hubble sequence and 1936 work ''The Realm of the Nebulae'', with their intermediate scale disks, a subset of the "early-type" galaxy population. Most elliptical galaxies are composed of older, low-mass stars, with a sparse interstellar medium and minimal star formation activity, and they tend to be surrounded by large numbers of globular clusters. Elliptical galaxies are believed to make up approximately 10–15% of galaxies in the Virgo Supercluster, and they are not the dominant type of galaxy in the universe overall. They are preferentially found close to the centers of galaxy clusters. Elliptical galaxies range in size from dwarf ellipticals with tens of millions of stars, to supergiants of over one hundred trillion stars that dominate their galaxy clusters. Originally, Ed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 1379
NGC 1379 is a low-luminosity elliptical galaxy in the southern constellation Fornax. It was discovered by William Herschel on December 25, 1835. At a distance of 60 million light-years, it is one of the closer members of the Fornax Cluster. It is located about 24' from the central galaxy, NGC 1399. NGC 1387 is the closest galaxy, and it is in the foreground of NGC 1379. Both are located in central part of the Fornax Cluster. NGC 1379 has a Hubble classification of E0. It is also an early-type galaxy, like most other elliptical galaxies in the Fornax Cluster. Its size on the night sky is 2.6' x 2.5' which is, combined with the estimated distance, proportional to its real size of 50,000 light-years. Despite their name, early-type galaxies are much older than spiral galaxies, and mostly comprise old, red-colored stars. Very little star formation occurs in these galaxies; the lack of star formation in elliptical galaxies appears to start at the center and then slowly propagates ou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 1374
NGC 1374 is a low-luminosity elliptical galaxy in the southern constellation Fornax. It was discovered by John Herschel on November 29, 1837. Location It is at a distance of 59 million light years. The galaxy may form a pair with another nearby galaxy, NGC 1375, but this is uncertain based on the estimated distance of NGC 1375. It is a member of the Fornax Cluster, a cluster of 200 galaxies, and it is positioned near the center of the cluster and central galaxy NGC 1399, while the closest galaxy after NGC 1375, outside the pair, is NGC 1373. NGC 1374's size on the night sky is 2.7 × 2.4 which, with the galaxy's distance, gives a diameter of 50,000 light-years. Classification NGC 1374 is an early-type galaxy with a Hubble classification of E1, indicating a flattening of 10%, but also it shows a subtle differentiation of light about halfway out of radius, which is indicating transition to S0 classification. It has a bright core surrounded by a soft hazy halo. Despite their ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hubble Classification
The Hubble sequence is a morphological classification scheme for galaxies invented by Edwin Hubble in 1926. It is often colloquially known as the Hubble tuning-fork diagram because the shape in which it is traditionally represented resembles a tuning fork. Hubble's scheme divided regular galaxies into three broad classes – ellipticals, lenticulars and spirals – based on their visual appearance (originally on photographic plates). A fourth class contains galaxies with an irregular appearance. The Hubble sequence is the most commonly used system for classifying galaxies, both in professional astronomical research and in amateur astronomy. Classes of galaxies Ellipticals On the left (in the sense that the sequence is usually drawn) lie the ellipticals. Elliptical galaxies have relatively smooth, featureless light distributions and appear as ellipses in photographic images. They are denoted by the letter E, followed by an integer ''n'' representing their degree of ell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minute And Second Of Arc
A minute of arc, arcminute (arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of one degree. Since one degree is of a turn (or complete rotation), one minute of arc is of a turn. The nautical mile (nmi) was originally defined as the arc length of a minute of latitude on a spherical Earth, so the actual Earth circumference is very near . A minute of arc is of a radian. A second of arc, arcsecond (arcsec), or arc second, denoted by the symbol , is of an arcminute, of a degree, of a turn, and (about ) of a radian. These units originated in Babylonian astronomy as sexagesimal subdivisions of the degree; they are used in fields that involve very small angles, such as astronomy, optometry, ophthalmology, optics, navigation, land surveying, and marksmanship. To express even smaller angles, standard SI prefixes can be employed; the milliarcsecond (mas) and microarcsecond (μas), for instance, are commonly used in astr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hubble Space Telescope
The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versatile, renowned both as a vital research tool and as a public relations boon for astronomy. The Hubble telescope is named after astronomer Edwin Hubble and is one of NASA's Great Observatories. The Space Telescope Science Institute (STScI) selects Hubble's targets and processes the resulting data, while the Goddard Space Flight Center (GSFC) controls the spacecraft. Hubble features a mirror, and its five main instruments observe in the ultraviolet, visible, and near-infrared regions of the electromagnetic spectrum. Hubble's orbit outside the distortion of Earth's atmosphere allows it to capture extremely high-resolution images with substantially lower background light than ground-based telescopes. It has recorded some of the most detaile ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Herschel
Frederick William Herschel (; german: Friedrich Wilhelm Herschel; 15 November 1738 – 25 August 1822) was a German-born British astronomer and composer. He frequently collaborated with his younger sister and fellow astronomer Caroline Herschel (1750–1848). Born in the Electorate of Hanover, William Herschel followed his father into the military band of Hanover, before emigrating to Great Britain in 1757 at the age of nineteen. Herschel constructed his first large telescope in 1774, after which he spent nine years carrying out sky surveys to investigate double stars. Herschel published catalogues of nebulae in 1802 (2,500 objects) and in 1820 (5,000 objects). The resolving power of the Herschel telescopes revealed that many objects called nebulae in the Messier catalogue were actually clusters of stars. On 13 March 1781 while making observations he made note of a new object in the constellation of Gemini. This would, after several weeks of verification and consultation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fornax Cluster
The Fornax Cluster is a cluster of galaxies lying at a distance of 19 megaparsecs (62 million light-years). It has an estimated mass of solar masses, making it the second richest galaxy cluster within 100 million light-years, after the considerably larger Virgo Cluster. It may be associated with the nearby Eridanus Group. It lies primarily in the constellation Fornax, with its southern boundaries partially crossing into the constellation of Eridanus, and covers an area of sky about 6° across or about 28 sq degrees. The Fornax Cluster is a particularly valuable source of information about the evolution of such clusters due to its relatively close proximity to the Sun. It also shows the gravitational effects of a merger of a galaxy subgroup with the main galaxy group, which in turn lends clues about the associated galactic superstructure. At the centre of the cluster lies NGC 1399. Other cluster members include NGC 1316 (the group's brightest galaxy), NGC 1365, NGC 1427A, N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
