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PGC 16389
LEDA/PGC 16389 is a Hubble-type dwarf irregular galaxy (dIrr) in the constellation Caelum in the southern sky. It is estimated to be 22 million light-years from the Milky Way The Milky Way or Milky Way Galaxy is the galaxy that includes the Solar System, with the name describing the #Appearance, galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars in other arms of the galax ... and forms an optical galaxy pair with APMBGC 252+125-117. References External links CDS PortalSIMBAD Astronomical DatabaseA cosmic optical illusion 16389 Dwarf irregular galaxies Caelum J02232199+3211492 {{galaxy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hubble Space Telescope
The Hubble Space Telescope (HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the Orbiting Solar Observatory, first space telescope, but it is one of the largest and most versatile, renowned as a vital research tool and as a public relations boon for astronomy. The Hubble Space Telescope is named after astronomer Edwin Hubble and is one of NASA's Great Observatories program, 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 spectrum, visible, and near-infrared regions of the electromagnetic spectrum. Hubble's orbit outside the distortion of atmosphere of Earth, Earth's atmosphere allows it to capture extremely high-resolution images with substantially lower background lig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caelum
Caelum is a faint constellation in the southern sky, introduced in the 1750s by Nicolas Louis de Lacaille and counted among the 88 modern constellations. Its name means "chisel" in Latin, and it was formerly known as Caelum Sculptorium ("Engraver's Chisel"); it is a rare word, unrelated to the far more common Latin ''caelum'', meaning "sky", "heaven", or "atmosphere". It is the eighth-smallest constellation, and subtends a solid angle of around 0.038 steradians, just less than that of Corona Australis. Due to its small size and location away from the plane of the Milky Way, Caelum is a rather barren constellation, with few objects of interest. The constellation's brightest star, Alpha Caeli, is only of apparent magnitude, magnitude 4.45, and only one other star, Gamma1 Caeli, (Gamma) γ1 Caeli, is brighter than magnitude 5 . Other notable objects in Caelum are RR Caeli, RR Caeli, a binary star with one known planet approximately away; X Caeli, X Cae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2MASS
The Two Micron All-Sky Survey, or 2MASS, was an astronomical survey of the whole sky in infrared light. It took place between 1997 and 2001, in two different locations: at the U.S. Fred Lawrence Whipple Observatory on Mount Hopkins, Arizona, and at the Cerro Tololo Inter-American Observatory in Chile, each using a 1.3-meter telescope for the Northern and Southern Hemisphere, respectively. It was conducted in the short-wavelength infrared at three distinct frequency bands ( J, H, and K) near 2 micrometres, from which the photometric survey with its HgCdTe detectors derives its name. 2MASS produced an astronomical catalog with over 300 million observed objects, including minor planets of the Solar System, brown dwarfs, low-mass stars, nebulae, star clusters and galaxies. In addition, 1 million objects were cataloged in the ''2MASS Extended Source Catalog'' (''2MASX''). The cataloged objects are designated with a "2MASS" and "2MASX"-prefix respectively. Catalog The fina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Southern Observatory
The European Organisation for Astronomical Research in the Southern Hemisphere, commonly referred to as the European Southern Observatory (ESO), is an intergovernmental organization, intergovernmental research organisation made up of 16 member states for ground-based astronomy. Created in 1962, ESO has provided astronomers with state-of-the-art research facilities and access to the southern sky. The organisation employs over 750 staff members and receives annual member state contributions of approximately €162 million. Its observatories are located in northern Chile. ESO has built and operated some of the largest and most technologically advanced telescopes. These include the 3.6 m New Technology Telescope, an early pioneer in the use of active optics, and the Very Large Telescope (VLT), which consists of four individual 8.2 m telescopes and four smaller auxiliary telescopes which can all work together or separately. The Atacama Large Millimeter Array observes the u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Astronomical Catalogues
An astronomical catalogue is a list or tabulation of astronomical objects, typically grouped together because they share a common type, morphology, origin, means of detection, or method of discovery. Astronomical catalogs are usually the result of an astronomical survey of some kind. 0–9 * 0ES — Einstein Slew Survey, version 0See p. 20, X-ray sources in SIMBAD, J. M. Hameury, C. Motch, and M. Pakull, ''Bull. Inf. Centre Données Stellaires'' 47, pp. 19–20, . * 1A, 2A, 3A — Lists of X-ray sources from the Ariel V satellite * 1C — First Cambridge Catalogue of Radio Sources * 1ES — Einstein Slew Survey * 1FGL, 2FGL — Lists of gamma-ray sources from the Fermi LAT, Large Area Telescope on board the Fermi Gamma-ray Space Telescope * 1RXH — ROSAT HRI Pointed Observations * 1RXS — ROSAT All-Sky Bright Source Catalogue, ROSAT All-Sky Survey Faint Source Catalog * 1SWASP — SuperWASP * 2A — see 1A * 2C — Second Cambridge Catalogue of Radio Sources * 2E — The Einste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Principal Galaxies Catalogue
The Principal Galaxies Catalogue (PGC) is an astronomical catalog published in 1989 that lists B1950 and J2000 equatorial coordinates and cross-identifications for 73,197 galaxies. It is based on the Lyon-Meudon Extragalactic Database (LEDA), which was originally started in 1983. 40,932 coordinates (56%) have standard deviations smaller than . A total of 131,601 names from the 38 most common sources are listed. Available mean data for each object are given: * 49,102 morphological descriptions, * 52,954 apparent major and minor axis, * 67,116 apparent magnitudes, * 20,046 radial velocities and * 24,361 position angles. The Lyon-Meudon Extragalactic Database was eventually expanded into HyperLEDA, a database of a few million galaxies. Galaxies in the original PGC catalogue are numbered with their original PGC number in HyperLEDA. Numbers have also been assigned for the other galaxies, although for those galaxies not in the original PGC catalogue, it is not recommended t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hubble Sequence
The Hubble sequence is a morphological classification scheme for galaxies published 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. It was invented by John Henry Reynolds and Sir James Jeans. The tuning fork 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 sometimes classified as a dwarf galaxy; others consider it a full-fledged galaxy. Dwarf galaxies' formation and activity are thought to be heavily influenced by interactions with larger galaxies. Astronomers identify numerous types of dwarf galaxies, based on their shape and composition. Formation One theory states that most galaxies, including dwarf galaxies, form in association with dark matter, or from gas that contains metals. However, NASA's Galaxy Evolution Explorer space probe identified new dwarf galaxies forming out of gases with low metallicity. These galaxies were located in the Leo Ring, a cloud of hydrogen and helium around two massive galaxies in the constellation Leo (constellation), Leo. Because of their small size, dwar ... [...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. This absence of structure in an irregular galaxy leads to little density waves in these galaxies. This makes irregular galaxies prime areas to study star formation without the effects of density waves. 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 may also be formed in galaxy collisions. Irregular galaxies are commonly small, about one tenth the mass of the Milky Way galaxy, though t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Southern Celestial Hemisphere
The southern celestial hemisphere, also called the Southern Sky, is the Southern Hemisphere, southern half of the celestial sphere; that is, it lies south of the celestial equator. This arbitrary sphere, on which seemingly fixed stars form constellations, diurnal motion, appears to rotate westward around a celestial pole, polar axis as the Earth Earth's rotation, rotates. At all times, the entire Southern Sky is visible from the geographic South Pole; less of the Southern Sky is visible the latitude, further north the observer is located. The northern counterpart is the northern celestial hemisphere. Astronomy In the context of astronomical discussions or writing about celestial cartography, celestial mapping, it may also simply then be referred to as the Southern Hemisphere. For the purpose of celestial mapping, the sky is considered by Astronomer, astronomers as the inside of a sphere divided in two halves by the celestial equator. The Southern Sky or Southern Hemisphere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light-year
A light-year, alternatively spelled light year (ly or lyr), is a unit of length used to express astronomical distances and is equal to exactly , which is approximately 9.46 trillion km or 5.88 trillion mi. As defined by the International Astronomical Union (IAU), a light-year is the distance that light travels in vacuum in one Julian year (365.25 days). Despite its inclusion of the word "year", the term should not be misinterpreted as a unit of time. The ''light-year'' is most often used when expressing distances to stars and other distances on a galactic scale, especially in non-specialist contexts and popular science publications. The unit most commonly used in professional astronomy is the parsec (symbol: pc, about 3.26 light-years). Definitions As defined by the International Astronomical Union (IAU), the light-year is the product of the Julian year (365.25 days, as opposed to the 365.2425-day Gregorian year or the 365.24219-day Tropical year that both approxim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milky Way
The Milky Way or Milky Way Galaxy is the galaxy that includes the Solar System, with the name describing the #Appearance, galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars in other arms of the galaxy, which are so far away that they cannot be individually distinguished by the naked eye. The Milky Way is a barred spiral galaxy with a Galaxy#Isophotal diameter, D25 isophotal diameter estimated at , but only about 1,000 light-years thick at the spiral arms (more at the bulge). Recent simulations suggest that a dark matter area, also containing some visible stars, may extend up to a diameter of almost 2 million light-years (613 kpc). The Milky Way has several List of Milky Way's satellite galaxies, satellite galaxies and is part of the Local Group of galaxies, forming part of the Virgo Supercluster which is itself a component of the Laniakea Supercluster. It is estimated to contain 100–400 billion stars and at least that number of pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
