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R99 (star)
R99 (HD 269445) is a star in the Large Magellanic Cloud in the constellation Dorado. It is classified as a possible luminous blue variable and is one of the most luminous stars known. R99 has a peculiar spectrum that has been described as OBf:pe, "unclassifiable", peculiar WN10, "similar to the unusual LBV HD 5980", "unique", and Ofpe/WN9. The Ofpe/WN9 type remains even though other stars of this type have been reclassified to types between WN9 and WN11. R99 has significant differences from those other stars which preclude it being given a simple WN spectral type: the ultraviolet spectrum is strongly blanketed over a different range of wavelengths; highly ionised iron lines are seen in absorption instead of emission; the H lines are unusually narrow and have no P Cygni profile; a lack of any significant absorption features near Hδ; a number of metal lines are unusually strong or weak compared to other stars of the type; there is a small unexplained infrared excess. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dorado (constellation)
Dorado (, ) is a constellation in the Southern Sky. It was named in the late 16th century and is now one of the IAU designated constellations, 88 modern constellations. Its name refers to the mahi-mahi (''Coryphaena hippurus''), which is known as ''dorado'' ("golden") in Spanish language, 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 (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 Freder ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultraviolet
Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs, Cherenkov radiation, and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights. The photons of ultraviolet have greater energy than those of visible light, from about 3.1 to 12 electron volts, around the minimum energy required to ionize atoms. Although long-wavelength ultraviolet is not considered an ionizing radiation because its photons lack sufficient energy, it can induce chemical reactions and cause many substances to glow or fluoresce. Many practical applications, including chemical and biological effects, are derived from the way that UV radiation can interact with organic molecules. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luminous Blue Variables
Luminous may refer to: Music * Luminous (group), a South Korean boy band * ''Luminous'' (EP), a 2004 EP by Cesium_137 * ''Luminous'' (John Hicks and Elise Wood album), 1985–88 * ''Luminous'' (The Horrors album), 2014 * ''Luminous'', an album by Chris Murphy * ''Luminous'', an album by Bill Nelson, 1991 * ''Luminous'', an album by Scandal, 2024 * "Luminous" (ClariS song), 2012 * "Luminous" (Jedward song), 2012 Other uses * ''Luminous'' (book), a 1998 short story collection by Greg Egan * Luminous (typeface), a foundry type made by Ludwig & Mayer * Luminous flame, a flame emitting visible light * Luminous mind, a term used in Buddhist doctrine * Luminous Mysteries, meditations on the Rosary in the Catholic Church * Luminous Productions, a defunct video game developer ** Luminous Engine, a video game engine * Luminous: The Symphony of Us, a fireworks-based nighttime spectacular at Disney's Epcot theme park * Project Luminous, a project by The Walt Disney Company that became ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henry Draper Catalogue Objects
Henry may refer to: People and fictional characters * Henry (given name), including lists of people and fictional characters * Henry (surname) * Henry, a stage name of François-Louis Henry (1786–1855), French baritone Arts and entertainment * Henry (2011 film), ''Henry'' (2011 film), a Canadian short film * Henry (2015 film), ''Henry'' (2015 film), a virtual reality film * ''Henry: Portrait of a Serial Killer'', a 1986 American crime film * Henry (comics), ''Henry'' (comics), an American comic strip created in 1932 by Carl Anderson * "Henry", a song by New Riders of the Purple Sage Places Antarctica * Henry Bay, Wilkes Land Australia *Henry River (New South Wales) *Henry River (Western Australia) Canada * Henry Lake (Vancouver Island), British Columbia * Henry Lake (Halifax County), Nova Scotia * Henry Lake (District of Chester), Nova Scotia New Zealand * Lake Henry (New Zealand) * Henry River (New Zealand) United States * Henry, Illinois * Henry, Indiana * Henry, Nebras ... [...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] |
Wolf–Rayet Stars
Wolf–Rayet (WR) can mean: * 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 ..., a type of evolved, massive star * Wolf–Rayet galaxy, which contains large numbers of Wolf–Rayet stars * Wolf–Rayet nebula, which surrounds a Wolf–Rayet star {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stars In The Large Magellanic Cloud
A star is a luminous spheroid of plasma held together by self-gravity. The nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night; their immense distances from Earth make them appear as fixed points of light. The most prominent stars have been categorised into constellations and asterisms, and many of the brightest stars have proper names. Astronomers have assembled star catalogues that identify the known stars and provide standardized stellar designations. The observable universe contains an estimated to stars. Only about 4,000 of these stars are visible to the naked eye—all within the Milky Way galaxy. A star's life begins with the gravitational collapse of a gaseous nebula of material largely comprising hydrogen, helium, and traces of heavier elements. Its total mass mainly determines its evolution and eventual fate. A star shines for most of its active life due to the thermonuclear fusion of hydrogen into helium in its core. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Most Massive Stars
This is a list of the most massive stars that have been discovered, in solar mass units (). Uncertainties and caveats Most of the masses listed below are contested and, being the subject of current research, remain under review and subject to constant revision of their masses and other characteristics. Indeed, many of the masses listed in the table below are inferred from theory, using difficult measurements of the stars' effective temperature, temperatures, metallicity, composition, and absolute magnitude, absolute brightnesses. All the masses listed below are uncertain: Both the theory and the measurements are pushing the limits of current knowledge and technology. Both theories and measurements could be incorrect. Complications with distance and obscuring clouds Since massive stars are rare, astronomers must look very far from Earth to find them. All the listed stars are many thousands of light years away, which makes measurements difficult. In addition to being far away, many ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infrared
Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those of red light (the longest waves in the visible spectrum), so IR is invisible to the human eye. IR is generally (according to ISO, CIE) understood to include wavelengths from around to . IR is commonly divided between longer-wavelength thermal IR, emitted from terrestrial sources, and shorter-wavelength IR or near-IR, part of the solar spectrum. Longer IR wavelengths (30–100 μm) are sometimes included as part of the terahertz radiation band. Almost all black-body radiation from objects near room temperature is in the IR band. As a form of EMR, IR carries energy and momentum, exerts radiation pressure, and has properties corresponding to both those of a wave and of a particle, the photon. It was long known that fires e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
P Cygni Profile
P Cygni (34 Cygni) is a variable star in the constellation Cygnus. The designation "P" was originally assigned by Johann Bayer in ''Uranometria'' as a nova. Located about 5,300 light-years (1,560 parsecs) from Earth, it is a hypergiant luminous blue variable (LBV) star of spectral type B1-2 Ia-0ep that is one of the most luminous stars in the Milky Way. Visibility The star is located about 5,000 to 6,000 light-years (1,500–1,800 parsecs) from Earth. Despite this vast distance, it is visible to the naked eye in suitable dark sky locations. It was unknown until the end of the 16th century, when it suddenly brightened to 3rd magnitude. It was first observed on 18 August (Gregorian) 1600 by Willem Janszoon Blaeu, a Dutch astronomer, mathematician and globe-maker. Bayer's atlas of 1603 assigned it the miscellaneous label P and the name has stuck ever since. After six years the star faded slowly, dropping below naked-eye visibility in 1626. It brightened again in 1655, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 5980
HD 5980 is a multiple star system on the outskirts of NGC 346 in the Small Magellanic Cloud (SMC) and is one of the brightest stars in the SMC. HD 5980 has at least three components among the List of most luminous stars, most luminous stars known: the unusual primary has a Wolf–Rayet star, Wolf–Rayet spectrum and has produced a luminous blue variable (LBV) outburst; the secondary, also a Wolf–Rayet star, forms an eclipsing spectroscopic binary with the primary star; and a more distant O-type star, O-type supergiant is also likely to be a binary. Discovery HD 5980 was first recorded in 1901 as the first object in a list of southern sky objects having peculiar spectra. It was described as "Type V", referring to the Stellar classification#Secchi classes, Secchi class for stars with emission lines. It was formally named HD 5980 in the first Henry Draper Catalogue where it was given the spectral type of Oa indicating strong emission bands. The spectral type was lat ... [...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] |
