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List Of Luminous Blue Variable Stars
This is a list of luminous blue variable stars in order of their distance from Earth. List Milky Way galaxy (confirmed LBVs) Milky Way galaxy (candidate LBVs) Magellanic Clouds The Large Magellanic Cloud (LMC) is around 163 kly distant and the Small Magellanic Cloud (SMC) is around 204 kly distant Andromeda Galaxy and Triangulum Galaxy The Andromeda Galaxy (M31) is 2.5 Mly distant and the Triangulum Galaxy is around 3.2 Mly distant Single LBV Galaxies See also * List of Wolf-Rayet stars * List of O-type stars References Lists of stars Luminous blue variables, {{DEFAULTSORT:Star systems within 100-150 light-years Star systems Lists by distance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luminous Blue Variable
Luminous blue variables (LBVs) are rare, massive, evolved stars that show unpredictable and sometimes dramatic variations in their spectra and brightness. They are also known as S Doradus variables after S Doradus, one of the brightest stars of the Large Magellanic Cloud. Discovery and history The LBV stars P Cygni and Eta Carinae, η Carinae have been known as unusual variables since the 17th century, but their true nature was not fully understood until late in the 20th century. In 1922 John Charles Duncan published the first three variable stars ever detected in an external galaxy, variables 1, 2, and 3, in the Triangulum Galaxy (M33). These were followed up by Edwin Hubble with three more in 1926: A, B, and C in M33. Then in 1929 Hubble added a list of variables detected in Messier 31, M31. Of these, Var A, Var B, Var C, and Var 2 in M33 and Var 19 in M31 were followed up with a detailed study by Hubble and Allan Sandage in 1953. Var 1 in M33 was excluded as being too faint a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HR Carinae
HR Carinae is a luminous blue variable star located in the constellation Carina. It is surrounded by a vast nebula of ejected nuclear-processed material because this star has a multiple shell expanding atmosphere. This star is among the most luminous stars in the Milky Way. It has very broad emission wings on the Balmer lines, reminiscent from the broad lines observed in the spectra of O and Wolf–Rayet stars. A distance of 5 kpc and a bolometric magnitude of −9.4 put HR Car among the most luminous stars of the galaxy. Discovery HR Carinae was first noticed at the start of the 20th century because of its Hβ emission. It was placed in Secchi class I, corresponding to modern A and F-type stars. It was catalogued in 1933 as a Be star and was discovered to be variable in 1940. A more detailed spectroscopic study gave it the type B2eq with emission line of hydrogen, helium, and ionised iron and P Cygni profiles on some lines. By 1970, HR Carinae and the similar vari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pistol Star And Nebula
A pistol is a type of handgun, characterised by a barrel with an integral chamber. The word "pistol" derives from the Middle French ''pistolet'' (), meaning a small gun or knife, and first appeared in the English language when early handguns were produced in Europe. In colloquial usage, the word "pistol" is often used as a generic term to describe ''any'' type of handgun, inclusive of revolvers (which have a single barrel and a separate cylinder housing multiple chambers) and the pocket-sized derringers (which are often multi-barrelled). The most common type of pistol used in the contemporary era is the semi-automatic pistol. The older single-shot and lever-action pistols are now rarely seen and used primarily for nostalgic hunting and historical reenactment. Fully-automatic machine pistols are uncommon in civilian usage because of their generally poor recoil-controllability (due to the lack of a buttstock) and strict laws and regulations governing their manufacture and sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pistol Star
The Pistol Star (or V4647 Sagittarii) is an extremely luminous blue hypergiant star, one of the most luminous and massive known stars in the Milky Way. It is one of many massive young stars in the Quintuplet cluster in the Galactic Center region. The star owes its name to the shape of the Pistol Nebula, which it illuminates. It is located approximately 25,000 light-years from Earth in the direction of Sagittarius. The star has a large mass comparable to V4998 Sagittarii and a luminosity 3.3 million times that of the Sun (). It would be visible to the naked eye as a 4th-magnitude star if it were not for the interstellar dust near the Center of the Milky Way that absorbs almost all of its visible light. Properties The Pistol Star was discovered using the Hubble Space Telescope in the early 1990s by Don Figer, an astronomer at UCLA. The star is thought to have ejected almost 10 solar masses of material in giant outbursts perhaps 4,000 to 6,000 years ago (as observed f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galactic Center
The Galactic Center is the barycenter of the Milky Way and a corresponding point on the rotational axis of the galaxy. Its central massive object is a supermassive black hole of about 4 million solar masses, which is called Sagittarius A*, a compact Astronomical radio source, radio source which is almost exactly at the galactic rotational center. The Galactic Center is approximately away from Earth in the direction of the constellations Sagittarius (constellation), Sagittarius, Ophiuchus, and Scorpius, where the Milky Way appears brightest, visually close to the Butterfly Cluster (M6) or the star Shaula, south to the Pipe Nebula. There are around 10 million stars within one parsec of the Galactic Center, dominated by red giants, with a significant population of massive supergiants and Wolf–Rayet stars from star formation in the region around 1 million years ago. The core stars are a small part within the much wider central region, called ''galactic bulge''. Discovery Be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
A Closer Look At Hubble’s 31st Anniversary Snapshot (51484874537)
A, or a, is the first letter and the first vowel letter of the Latin alphabet, used in the modern English alphabet, and others worldwide. Its name in English is '' a'' (pronounced ), plural ''aes''. It is similar in shape to the Ancient Greek letter alpha, from which it derives. The uppercase version consists of the two slanting sides of a triangle, crossed in the middle by a horizontal bar. The lowercase version is often written in one of two forms: the double-storey and single-storey . The latter is commonly used in handwriting and fonts based on it, especially fonts intended to be read by children, and is also found in italic type. In English, '' a'' is the indefinite article, with the alternative form ''an''. Name In English, the name of the letter is the ''long A'' sound, pronounced . Its name in most other languages matches the letter's pronunciation in open syllables. History The earliest known ancestor of A is ''aleph''—the first letter of the Phoenician ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AG Carinae
AG Carinae (AG Car) is a star in the constellation of Carina. It is classified as a luminous blue variable (LBV) and is one of the most luminous stars in the Milky Way. The great distance (20,000 light-years) and intervening dust mean that the star is not usually visible to the naked eye; its apparent brightness varies erratically between magnitude 5.7 and 9.0. In 1914, Harry Edwin Wood announced his discovery that this star, then called CPD−59°2860, is a variable star, based on photographic plates taken in 1911 and 1914. It was given its variable star designation, AG Carinae, in 1921. Description The star is surrounded by a nebula of ejected material at 0.4–1.2 pc from the star. The nebula contains around , all lost from the star around 10,000 years ago. There is an 8.8-parsec-wide empty cavity in the interstellar medium around the star, presumably cleared by fast winds earlier in the star's life. AG Carinae is apparently in a transitional phase between a massiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
