|
List Of Most Distant Stars
This is a list of the most distant individually seen stars discovered, a list of the most distant stars that are separately known, resolved as individual stars, or as multiple star systems. It is not a list of sources that should contain stars that are distant but no separate stars within that source are separately known, such as unresolved stars in star clusters, galaxies, galaxy clusters. Distances to stars may be determined through parallax measurements, use of standard references such as cepheid variables or Type Ia supernovas to the object in which the star resides, or redshift measurement. Spectroscopic redshift measurement is preferred, while photometric redshift measurement is also used to identify candidate high redshift sources. The symbol ''z'' represents redshift Most distant stars List of most distant stars by type List of most distant stars by event type Timeline of most distant star recordholders The succession of most distant separately known st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Star
A star is a luminous spheroid of plasma (physics), plasma held together by Self-gravitation, self-gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night sky, night; their immense distances from Earth make them appear as fixed stars, fixed points of light. The most prominent stars have been categorised into constellations and asterism (astronomy), 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 star formation, begins with the gravitational collapse of a gaseous nebula of material largely comprising hydrogen, helium, and traces of heavier elements. Its stellar mass, total mass mainly determines it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yellow Supergiant
A yellow supergiant (YSG) is a star, generally of spectral type F or G, having a supergiant luminosity class (e.g. Ia or Ib). They are stars that have evolved away from the main sequence, expanding and becoming more luminous. Yellow supergiants are hotter and smaller than red supergiants; naked eye examples include Polaris, Alpha Leporis, Alpha Persei, Delta Canis Majoris and Iota¹ Scorpii. Many of them are variable stars, mostly pulsating Cepheids such as δ Cephei itself. Spectrum Yellow supergiants generally have spectral types of F and G, although sometimes late A or early K stars are included. These spectral types are characterised by hydrogen lines that are very strong in class A, weakening through F and G until they are very weak or absent in class K. Calcium H and K lines are present in late A spectra, but stronger in class F, and strongest in class G, before weakening again in cooler stars. Lines of ionised metals are strong in class A, weaker in class F and G, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parsec
The parsec (symbol: pc) is a unit of length used to measure the large distances to astronomical objects outside the Solar System, approximately equal to or (AU), i.e. . The parsec unit is obtained by the use of parallax and trigonometry, and is defined as the distance at which 1 AU subtended angle, subtends an angle of one arcsecond ( of a degree (angle), degree). The nearest star, Proxima Centauri, is about from the Sun: from that distance, the gap between the Earth and the Sun spans slightly less than one arcsecond. Most Naked-eye stars, stars visible to the naked eye are within a few hundred parsecs of the Sun, with the most distant at a few thousand parsecs, and the Andromeda Galaxy at over 700,000 parsecs. The word ''parsec'' is a shortened form of ''a distance corresponding to a parallax of one second'', coined by the British astronomer Herbert Hall Turner in 1913. The unit was introduced to simplify the calculation of astronomical distances from raw observational data. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 5468
NGC 5468 is an intermediate spiral galaxy located in the constellation Virgo. It is located at a distance of about 140 million light-years from Earth, which, given its apparent dimensions, means that NGC 5468 is about 110,000 light-years across. It was discovered by William Herschel on 5 March 1785. NGC 5468 is seen face-on, and the spiral pattern is open. The two principal arms emanate from a small bar and start to branch into several thin fragments after some distance. Three large H II regions and some fainter ones can be seen in the images of the Carnegie Atlas of Galaxies.Sandage, A., Bedke, J. (1994), ''The Carnegie Atlas of Galaxies. Volume I'', Carnegie Institution of Washington These regions feature intense star formation. SN 2005P was located at the edge of one of these regions. As of 2024, NGC 5468 is the most distant galaxy in which Hubble Space Telescope has detected Cepheid variable stars, which are important milepost markers for measuring distances. NGC 5468 forms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SDSS J1229+1122
SDSS J1229+1122 (SDSS J122952.66+112227.8) is a blue supergiant O-type star in the tail of dwarf irregular galaxy IC 3418. It illuminates a nebula clump of gas, and was discovered from the spectrum of the illumination source. The clump of gas resides in a tail caused by ram pressure stripping of gas from the galaxy by the galaxy cluster. It was determined to be a blue supergiant through analysis of its spectrum taken with the 8m Subaru telescope. The discovery was made by Youichi Ohyama and Ananda Hota, using the Subaru Telescope. This discovery was then followed up with the AstroSat to image it with finer angular resolution in the ultraviolet than that of GALEX. With addition of HST optical data the astronomers believe that the ram pressure stripped tail of IC3418 many have many such young star forming clumps and potentially single O-type stars. Until the discovery of the doubly gravitationally lensed MACS J1149 Lensed Star 1 (also known as Icarus) in 2018, SDS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AT 2018kle
AT or at may refer to: Geography Austria * Austria (ISO 2-letter country code) * .at, Internet country code top-level domain United States * Atchison County, Kansas (county code) * The Appalachian Trail (A.T.), a 2,180+ mile long mountainous trail in the Eastern United States Elsewhere * Antigua and Barbuda, World Meteorological Organization country code * Ashmore and Cartier Islands (FIPS 10-4 territory code, and obsolete NATO country code) * At, Bihar, village in Aurangabad district of Bihar, India * Province of Asti, Italy (ISO 3166-2:IT code) * Australia, LOC MARC code Politics * Awami Tahreek a left-wing Pakistani political party Science and technology Computing * @ (or "at sign"), the punctuation symbol now typically used in e-mail addresses and tweets) * at (command), used to schedule tasks or other commands to be performed or run at a certain time * IBM Personal Computer/AT ** AT (form factor) for motherboards and computer cases ** AT connector, a five-pin ... [...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] |
International Astronomical Union
The International Astronomical Union (IAU; , UAI) is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and development through global cooperation. It was founded on 28 July 1919 in Brussels, Belgium and is based in Paris, France. The IAU is composed of individual members, who include both professional astronomers and junior scientists, and national members, such as professional associations, national societies, or academic institutions. Individual members are organised into divisions, committees, and working groups centered on particular subdisciplines, subjects, or initiatives. the Union had 85 national members and 12,734 individual members, spanning 90 countries and territories. Among the key activities of the IAU is serving as a forum for scientific conferences. It sponsors nine annual symposia and holds a triannual General Assembly that sets policy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AT 2022zmn
AT or at may refer to: Geography Austria * Austria (ISO 2-letter country code) * .at, Internet country code top-level domain United States * Atchison County, Kansas (county code) * The Appalachian Trail (A.T.), a 2,180+ mile long mountainous trail in the Eastern United States Elsewhere * Antigua and Barbuda, World Meteorological Organization country code * Ashmore and Cartier Islands (FIPS 10-4 territory code, and obsolete NATO country code) * At, Bihar, village in Aurangabad district of Bihar, India * Province of Asti, Italy (ISO 3166-2:IT code) * Australia, LOC MARC code Politics * Awami Tahreek a left-wing Pakistani political party Science and technology Computing * @ (or "at sign"), the punctuation symbol now typically used in e-mail addresses and tweets) * at (command), used to schedule tasks or other commands to be performed or run at a certain time * IBM Personal Computer/AT ** AT (form factor) for motherboards and computer cases ** AT connector, a five-pin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
O-type Star
An O-type star is a hot, blue star of spectral type O in the Yerkes classification system employed by astronomers. They have surface temperatures in excess of 30,000 kelvins (K). Stars of this type have strong absorption lines of ionised helium, strong lines of other ionised elements, and hydrogen and neutral helium lines weaker than spectral type B. Stars of this type are very rare, but because they are very bright, they can be seen at great distances; out of the 90 brightest stars as seen from Earth, 4 are type O. Due to their high mass, O-type stars end their lives rather quickly in violent supernova explosions, resulting in black holes or neutron stars. Most of these stars are young massive main sequence, giant, or supergiant stars, but also some central stars of planetary nebulae, old low-mass stars near the end of their lives, which typically have O-like spectra. O-type stars are typically found in regions of active star formation, such as the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
