|
HD 37974
HD 37974 (or R 126) a variable star, variable B(e) star, B[e] hypergiant in the Large Magellanic Cloud. It is surrounded by an unexpected dust disk. Properties R126, formally RMC (Radcliffe observatory Magellanic Cloud) 126, is a massive luminous star with several unusual properties. It exhibits the B[e] phenomenon where Forbidden mechanism, forbidden emission lines appear in the spectrum due to extended circumstellar envelope, circumstellar material. Its spectrum also shows normal (permitted) emission lines formed in denser material closer to the star, indicative of a power stellar wind. The spectra include silicate and polycyclic aromatic hydrocarbon (PAH) features that suggest a dusty disc. The star itself is a hot supergiant thought to be seventy times more massive than the Sun and over a million times more luminous. It has evolved away from the main sequence (being an O-class star, when it was in MS) and is so luminous and large that it is losing material through its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supersized Disk
''Supersized'' is the debut studio album of drum and bass, drum & bass DJ, producer and musician Danny Byrd. It was released on 26 May 2008 through Hospital Records. Singles * "Shock Out" was the first single released from the album, it was released on 4 February 2008. * "From Bath With Love" was the second single released from the album, it was released on 28 July 2008. * "Red Mist" was the third single released from the album, it was released on 26 June 2009. Track listing Release history References {{Authority control 2008 debut albums Danny Byrd albums Hospital Records albums ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emission Line
A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from emission or absorption of light in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used to identify atoms and molecules. These "fingerprints" can be compared to the previously collected ones of atoms and molecules, and are thus used to identify the atomic and molecular components of stars and planets, which would otherwise be impossible. Types of line spectra Spectral lines are the result of interaction between a quantum system (usually atoms, but sometimes molecules or atomic nucleus, atomic nuclei) and a single photon. When a photon has about the right amount of photon energy, energy (which is connected to its frequency) to allow a change in the energy state of the system (in the case of an atom this is usually an electron changing Electron configuration, orbitals), the photon is absorbed. Then the energy will be spontaneously ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stars In The Large Magellanic Cloud
A star is an astronomical object comprising a luminous spheroid of plasma held together by its gravity. The nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night, but 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 composed primarily of hydrogen, along with helium and trace amounts of heavier elements. Its total mass is the main factor determining its evolution and eventual fate. A star shines for most of its active life due ... [...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 masses (). 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' temperatures and 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. For example, VV Cephei could be between , or , depending on which property of the star is examined. 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 addi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luminous Blue Variable
Luminous blue variables (LBVs) are 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. They are extraordinarily rare, with just 20 objects listed in the General Catalogue of Variable Stars as SDor, and a number of these are no longer considered LBVs. Discovery and history The LBV stars P Cygni and 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 M31. Of these, Var A, Var B, Var C, and Var 2 in M33 and Var ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S Doradus
S Doradus (also known as S Dor) is one of the brightest stars in the Large Magellanic Cloud (LMC), a satellite galaxy of the Milky Way, located roughly 160,000 light-years away. The star is a luminous blue variable, and one of the most luminous stars known, having a luminosity varying widely above and below 1,000,000 times the luminosity of the Sun, although it is too far away to be seen with the naked eye. History S Doradus was noted in 1897 as an unusual and variable star, of Secchi type I with bright lines of Hα, Hβ, and Hγ. The formal recognition as a variable star came the assignment of the name S Doradus in 1904 in the second supplement to Catalogue of Variable Stars. S Dor was observed many times over the coming decades. In 1924, it was described as "P Cygni class" and recorded at photographic magnitude 9.5 In 1925, its absolute magnitude was estimated at −8.9. In 1933 it was listed as a 9th-magnitude Beq star with bright hydrogen lines. It was the mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
α Cygni Variable
Alpha Cygni variables are variable stars which exhibit non-radial pulsations, meaning that some portions of the stellar surface are contracting at the same time other parts expand. They are supergiant stars of spectral types B or A. Variations in brightness on the order of 0.1 magnitudes are associated with the pulsations, which often seem irregular, due to beating of multiple pulsation periods. The pulsations typically have periods of several days to several weeks. The prototype of these stars, Deneb Deneb () is a first-magnitude star in the constellation of Cygnus, the swan. Deneb is one of the vertices of the asterism known as the Summer Triangle and the "head" of the Northern Cross. It is the brightest star in Cygnus and th ... (α Cygni), exhibits fluctuations in brightness between magnitudes +1.21 and +1.29. Small amplitude rapid variations have been known in many early supergiant stars, but they were not formally grouped into a class until the 4th edit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kuiper Belt
The Kuiper belt () is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune at 30 astronomical units (AU) to approximately 50 AU from the Sun. It is similar to the asteroid belt, but is far larger—20 times as wide and 20–200 times as massive. Like the asteroid belt, it consists mainly of small bodies or remnants from when the Solar System formed. While many asteroids are composed primarily of rock and metal, most Kuiper belt objects are composed largely of frozen volatiles (termed "ices"), such as methane, ammonia, and water. The Kuiper belt is home to most of the objects that astronomers generally accept as dwarf planets: Orcus, Pluto, Haumea, Quaoar, and Makemake. Some of the Solar System's moons, such as Neptune's Triton and Saturn's Phoebe, may have originated in the region. The Kuiper belt was named after Dutch astronomer Gerard Kuiper, although he did not predict its existence. In 1992, minor planet (15760) Albion was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 268835
HD 268835 (or R66) (30 SM) is one of two stars that were identified by NASA's Spitzer Space Telescope in the Milky Way's nearest neighbor galaxy, the Large Magellanic Cloud (the other being R 126 or HD 37974), as being circled by monstrous dust disks that are theorised to be the origin of planets. Significance Both HD 268835 and HD 37974 are classified as hypergiants, very large and very bright. The dust cloud around them surprised astronomers because stars as big as these were thought to be inhospitable to planet formation as they have very strong winds making it difficult/impossible for the dust clouds to "condense" into planets. ''"We do not know if planets like those in our solar system are able to form in the highly energetic, dynamic environment of these massive stars, but if they could, their existence would be a short and exciting one"'' said Charles Beichman, an astronomer at NASA's Jet Propulsion Laboratory and the California Institute of Technology, both in Pasa ... [...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 spectra showing prominent broad emission lines of ionised helium and highly ionised nitrogen or carbon. The spectra indicate very high surface enhancement of heavy elements, depletion of hydrogen, and strong stellar winds. The surface temperatures of known Wolf–Rayet stars range from 20,000 K to around 210,000 K, hotter than almost all other kinds of stars. They were previously called W-type stars referring to their spectral classification. Classic (or population I) Wolf–Rayet stars are evolved, massive stars that have completely lost their outer hydrogen and are 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; they are young extremely massive stars still fusing hydrogen at the core, with helium and nitrogen exposed at the surface by strong mixing and radia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polycyclic Aromatic Hydrocarbon
A polycyclic aromatic hydrocarbon (PAH) is a class of organic compounds that is composed of multiple aromatic rings. The simplest representative is naphthalene, having two aromatic rings and the three-ring compounds anthracene and phenanthrene. PAHs are uncharged, non-polar and planar. Many are colorless. Many of them are found in coal and in oil deposits, and are also produced by the combustion of organic matter—for example, in engines and incinerators or when biomass burns in forest fires. Polycyclic aromatic hydrocarbons are discussed as possible starting materials for abiotic syntheses of materials required by the earliest forms of life. Nomenclature and structure The terms polyaromatic hydrocarbon or polynuclear aromatic hydrocarbon are also used for this concept. By definition, polycyclic aromatic hydrocarbons have multiple rings, precluding benzene from being considered a PAH. Some sources, such as the US EPA and CDC, consider naphthalene to be the simplest PAH. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.png "Click for more on -> Luminous Blue Variable")
