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R136
R136 (formerly known as RMC 136 from the Radcliffe Observatory Magellanic Clouds catalogue) is the central concentration of stars in the NGC 2070 star cluster, which lies at the centre of the Tarantula Nebula in the Large Magellanic Cloud. When originally named it was an unresolved stellar object (catalogued as HD 38268 and Wolf-Rayet star Brey 82) but is now known to include 72 class O and Wolf–Rayet stars within 5 parsecs (20 arc seconds) of the centre of the cluster. The extreme number and concentration of young massive stars in this part of the LMC qualifies it as a starburst region. Properties R136 produces most of the energy that makes the Tarantula Nebula visible. The estimated mass of the cluster is 450,000 solar masses, suggesting it may become a globular cluster in the future. R136 has around 200 times the stellar density of a typical OB association such as Cygnus OB2. The central R136 concentration of the cluster is about 2 parsecs across, although the whole ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
R136a1
R136a1 (short for RMC 136a1) is one of the List of most massive stars, most massive and list of most luminous stars, luminous stars known, at nearly and nearly 4.7 million , and is also one of the List of hottest stars, hottest, at around . It is a Wolf–Rayet star at the center of R136, the central concentration of stars of the large NGC 2070 open cluster in the Tarantula Nebula (30 Dorado, Doradus) in the Large Magellanic Cloud. The cluster can be seen in the far southern celestial hemisphere with binoculars or a small telescope, at magnitude 7.25. R136a1 itself is 100 times fainter than the cluster and can only be resolved using speckle interferometry. Discovery In 1960, a group of astronomers working at the Radcliffe Observatory in Pretoria made systematic measurements of the apparent magnitude, brightness and spectrum, spectra of bright stars in the Large Magellanic Cloud (LMC). Among the objects cataloged was R136, RMC 136 (Radcliffe observatory Magellanic Cloud ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
R136a2
R136a2 (RMC 136a2) is a Wolf-Rayet star residing near the center of the R136, the central concentration of stars of the large NGC 2070 open cluster in the Tarantula Nebula, a massive H II region in the Large Magellanic Cloud which is a nearby satellite galaxy of the Milky Way. It has one of the highest confirmed masses and luminosities of any known star, at about and 3.5 million respectively. Discovery In 1960, a group of astronomers working at the Radcliffe Observatory in Pretoria made systematic measurements of the brightness and spectra of bright stars in the Large Magellanic Cloud. Among the objects cataloged was RMC 136, (Radcliffe Observatory Magellanic Cloud Catalogue, Catalog number 136) the central "star" of 30 Doradus. Subsequent observations showed that R136 was located in the center of a giant H II region that was a center of intense star formation in the immediate vicinity of the observed stars. In the early 1980s, R136a was first resolved using speck ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
R136a3
R136a3 is a Wolf–Rayet star in R136, a massive star cluster located in Dorado. It is located near R136a1, the most massive and luminous star known. R136a3 is itself one of the List of most massive stars, most massive and List of most luminous stars, most luminous stars known at about 179 times more massive and 5 million times more luminous than the Sun. The formal name of the star is RMC 136a3, standing for ''Radcliffe observatory, Magellanic Clouds, 136a3''. The RMC survey identified luminous objects in the Large Magellanic Cloud and one of the brightest was RMC 136. This is now commonly shortened to R136, which is now known to be an extremely young dense open cluster at the core of the NGC 2070 cluster in the Tarantula Nebula. R136 was eventually resolved and the brightest "star" at the centre was termed R136a. This was further resolved into multiple components, one of which is R136a3. Although R136a3 has a Wolf-Rayet spectral type dominated by intense emissi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
R136c
R136c is a likely binary star located in R136, a tight knot of stars at the centre of NGC 2070, an open cluster weighing 450,000 solar masses and containing 10,000 stars. At and 3.8 million , it is one of the most massive stars known and one of the most luminous, along with being one of the hottest, at over . It was first resolved and named by Feitzinger in 1980, along with R136a and R136b. Description R136c is a Wolf–Rayet star of the spectral type WN5h and with a temperature of , making it one of hottest stars known. It is one of the most massive stars known, with a mass of , and it is one of the most luminous stars known, with a luminosity of 3.8 million . The extreme luminosity is produced by the CNO fusion process in its highly compressed hot core. Typical of all Wolf–Rayet stars, R136c has been losing mass by means of a strong stellar wind with speeds over and mass loss rates in excess of solar masses per year. It is strongly suspected to be a binary, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
R136b
R136b is a blue supergiant star in the R136 cluster in the Large Magellanic Cloud. It is one of the most massive and most luminous stars known. It is found in the dense R136 open cluster at the centre of NGC 2070 in the Tarantula Nebula. R136b has the spectral type of Wolf–Rayet star, with strong emission lines. Although it shows enhanced helium and nitrogen at its surface, it is still a very young star, still burning hydrogen in its core via the CNO cycle, and still effectively a main sequence In astronomy, the main sequence is a classification of stars which appear on plots of stellar color index, color versus absolute magnitude, brightness as a continuous and distinctive band. Stars on this band are known as main-sequence stars or d ... object. Others studies classify the spectrum as a hot supergiant with emission lines of ionised nitrogen and helium, still considering it to be a young star at the core-hydrogen-burning stage, the unusual spectrum caused by s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VFTS 682
VFTS 682 is a Wolf–Rayet star in the Large Magellanic Cloud. It is located over north-east of the massive cluster R136 in the Tarantula Nebula. It is 138 times the mass of the Sun and 3.2 million times more luminous, which makes it one of the most massive and most luminous stars known. Discovery VFTS 682 is a prominent infrared source in the Large Magellanic Cloud and has been catalogued numerous times. In 1992 it was identified as entry 153 in a list of possible protostars. In 2009 it was again classified as a probable young stellar object on account of its exceptional infrared luminosity. The VLT-FLAMES Tarantula survey (VFTS) examined 800 massive stars in detail and determined a spectral type of WN5h for VFTS 682. It is heavily reddened and visually several magnitudes fainter than other stars of similar luminosity and temperature in the 30 Doradus region. Runaway VFTS 682 is in the large star-forming region of the Tarantula Nebula, but is not within a dense mas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wolf–Rayet Star
Wolf–Rayet stars, often abbreviated as WR stars, are a rare heterogeneous set of stars with unusual spectroscopy, spectra showing prominent broad emission lines of ionised helium and highly ionised nitrogen or carbon. The spectra indicate very high surface enhancement of Stellar nucleosynthesis, heavy elements, depletion of hydrogen, and strong stellar winds. The Effective temperature, surface temperatures of known Wolf–Rayet stars range from 20,000 Kelvin (unit), K to around 210,000 Kelvin (unit), K, hotter than almost all other kinds of stars. They were previously called W-type stars referring to their Stellar classification, spectral classification. Classic (or population I) Wolf–Rayet stars are Stellar evolution, evolved, massive stars that have completely lost their outer hydrogen and are nuclear fusion, fusing helium or heavier elements in the core. A subset of the population I WR stars show hydrogen lines in their spectra and are known as WNh stars; the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tarantula Nebula
The Tarantula Nebula (also known as 30 Doradus) is a large H II region in the Large Magellanic Cloud (LMC), forming its south-east corner (from Earth, Earth's perspective). Discovery The Tarantula Nebula was observed by Nicolas-Louis de Lacaille during an expedition to the Cape of Good Hope between 1751 and 1753. He cataloged it as the second of the "Nebulae of the First Class", "Nebulosities not accompanied by any star visible in the telescope of two feet". It was described as a diffuse nebula 20' across. Johann Elert Bode, Johann Bode included the Tarantula in his 1801 ''Uranographia'' star atlas and listed it in the accompanying ''Allgemeine Beschreibung und Nachweisung der Gestirne'' catalog as number 30 in the constellation "Xiphias or Dorado". Instead of being given a stellar magnitude, it was noted to be nebulous. The name Tarantula Nebula arose in the mid-20th century from its appearance in deep photographic exposures. 30 Doradus has often been treated as the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apparent Magnitude
Apparent magnitude () is a measure of the Irradiance, brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction (astronomy), extinction of the object's light caused by interstellar dust along the sightline, line of sight to the observer. Unless stated otherwise, the word ''magnitude'' in astronomy usually refers to a celestial object's apparent magnitude. The magnitude scale likely dates to before the ancient Ancient Greek astronomy#Astronomy in the Greco-Roman and Late Antique eras, Roman astronomer Ptolemy, Claudius Ptolemy, whose Star catalogue, star catalog popularized the system by listing stars from First-magnitude star, 1st magnitude (brightest) to 6th magnitude (dimmest). The modern scale was mathematically defined to closely match this historical system by Norman Robert Pogson, Norman Pogson in 1856. The scale is reverse logarithmic scale, logarithmic: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 2070
NGC 2070 (also known as Caldwell 103) is a large open cluster and candidate super star cluster forming the heart of the bright region in the centre-south-east of the Large Magellanic Cloud. This cluster was discovered by French astronomer Nicolas-Louis de Lacaille in 1752. It is at the centre of the Tarantula Nebula and produces most of the energy that makes the latter's gas and dust visible. Its central condensation is the star cluster R136, one of the most energetic star clusters known. Among its stars are many of great dimension, including the second most massive star known, R136a1 R136a1 (short for RMC 136a1) is one of the List of most massive stars, most massive and list of most luminous stars, luminous stars known, at nearly and nearly 4.7 million , and is also one of the List of hottest stars, hottest, at around ..., at 215 and 6.16 million . References External links * * {{DEFAULTSORT:NGC 2070 2070 Tarantula Nebula Dorado Open clusters Large Mage ... [...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] |
Dorado
Dorado (, ) is a constellation in the Southern Sky. It was named in the late 16th century and is now one of the 88 modern constellations. Its name refers to the mahi-mahi (''Coryphaena hippurus''), which is known as ''dorado'' ("golden") in Spanish, although it has also been depicted as a swordfish. Dorado contains most of the Large Magellanic Cloud, the remainder being in the constellation Mensa. The South Ecliptic pole also lies within this constellation. Even though the name Dorado is not Latin but Spanish, astronomers give it the Latin genitive form ''Doradus'' when naming its stars; it is treated (like the adjacent asterism Argo Navis) as a feminine proper name of Greek origin ending in -ō (like ''Io'' or ''Callisto'' or ''Argo''), which have a genitive ending ''-ūs''. History Dorado was one of twelve constellations named by Petrus Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman. It appeared: * On a celestial globe published in 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
