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Theta Piscium
Theta Piscium, Latinized from θ Piscium, is a single, orange-hued star in the zodiac constellation of Pisces, the fish. The annual parallax shift of this star was measured during the Hipparcos mission as 21.96 mas, which yields a distance estimate of about 149 light years. It is a faint star but visible to the naked eye with an apparent visual magnitude of 4.27. The star is moving away from the Sun with a radial velocity of +6 km/s. At the estimated age of 2.5 billion years, this is an aging giant star with a stellar classification of K1 III, which means it has exhausted the supply of hydrogen at its core. It is a red clump star, indicating it is on the horizontal branch of its evolution and is generating energy through helium fusion at its core. Theta Piscium has 158% of the Sun's mass and its outer atmosphere has swollen to about 11 times the girth of the Sun. It is brighter yet cooler than the Sun, radiating 51.3 times the Sun's lumi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pisces (constellation)
Pisces is a constellation of the zodiac. Its vast bulk – and main asterism viewed in most European cultures per Greco-Roman antiquity as a distant pair of fishes connected by one cord each that join at an apex – are in the Northern celestial hemisphere. Its old astronomical symbol is (♓︎). Its name is Latin for "fishes". It is between Aquarius, of similar size, to the southwest and Aries, which is smaller, to the east. The ecliptic and the celestial equator intersect within this constellation and in Virgo. This means the sun passes directly overhead of the equator, on average, at approximately this point in the sky, at the March equinox. Features The March equinox is currently located in Pisces, due south of ω Psc, and, due to precession, slowly drifting due west, just below the western fish towards Aquarius. Stars * Alrescha ("the cord"), otherwise Alpha Piscium (α Psc), 309.8 lightyears, class A2, magnitude 3.62. Variable binary star. * Fumalsamakah ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sun's Mass
The solar mass () is a standard unit of mass in astronomy, equal to approximately . It is often used to indicate the masses of other stars, as well as stellar clusters, nebulae, galaxies and black holes. It is approximately equal to the mass of the Sun. This equates to about two nonillion (short scale), two quintillion (long scale) kilograms or 2000 quettagrams: The solar mass is about times the mass of Earth (), or times the mass of Jupiter (). History of measurement The value of the gravitational constant was first derived from measurements that were made by Henry Cavendish in 1798 with a torsion balance. The value he obtained differs by only 1% from the modern value, but was not as precise. The diurnal parallax of the Sun was accurately measured during the transits of Venus in 1761 and 1769, yielding a value of (9 arcseconds, compared to the present value of ). From the value of the diurnal parallax, one can determine the distance to the Sun from the geometry of E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
K-type Giants , an unusual kind of asteroid
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K-type may refer to: *AEC K-type, a bus chassis *K-type star, a stellar spectral classification *K-type filter, a type of electronic filter *K-type asteroid K-type asteroids are relatively uncommon asteroids with a moderately reddish spectrum shortwards of 0.75 μm, and a slight bluish trend longwards of this. They have a low albedo. Their spectrum resembles that of CV and CO meteorites. A larger K t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monthly Notices Of The Royal Astronomical Society
''Monthly Notices of the Royal Astronomical Society'' (MNRAS) is a peer-reviewed scientific journal covering research in astronomy and astrophysics. It has been in continuous existence since 1827 and publishes letters and papers reporting original research in relevant fields. Despite the name, the journal is no longer monthly, nor does it carry the notices of the Royal Astronomical Society. History The first issue of MNRAS was published on 9 February 1827 as ''Monthly Notices of the Astronomical Society of London'' and it has been in continuous publication ever since. It took its current name from the second volume, after the Astronomical Society of London became the Royal Astronomical Society (RAS). Until 1960 it carried the monthly notices of the RAS, at which time these were transferred to the newly established ''Quarterly Journal of the Royal Astronomical Society'' (1960–1996) and then to its successor journal ''Astronomy & Geophysics'' (since 1997). Until 1965, MNRAS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chinese Star Names
Chinese star names (Chinese: , ''xīng míng'') are named according to ancient Chinese astronomy and astrology. The sky is divided into star mansions (, ''xīng xiù'', also translated as "lodges") and asterisms (, ''xīng guān''). The system of 283 asterisms under Three Enclosures and Twenty-eight Mansions was established by Chen Zhuo of the Three Kingdoms period, who synthesized ancient constellations and the asterisms created by early astronomers Shi Shen, Gan De and Wuxian. Since the Han and Jin Dynasties, stars have been given reference numbers within their asterisms in a system similar to the Bayer or Flamsteed designations, so that individual stars can be identified. For example, Deneb (α Cyg) is referred to as (''Tiān Jīn Sì'', the Fourth Star of Celestial Ford). In the Qing Dynasty, Chinese knowledge of the sky was improved by the arrival of European star charts. ''Yixiang Kaocheng'', compiled in mid-18th century by then deputy Minister of Rites Ignaz Kögler, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Omega Piscium
Omega Piscium (Omega Psc, ω Piscium, ω Psc) is a star approximately 106 light years away from Earth, in the constellation Pisces. It has a spectral type of F4IV, meaning it is a subgiant/dwarf star, and it has a temperature of 6,600 kelvins. It may or may not be a close binary star system. Variations in its spectrum were once interpreted as giving it an orbital period of 2.16 days, but this claim was later debunked as false. It is 20 times brighter than the Sun and is 1.8 times greater in mass, if it is a single star. It is part of the drawn asterism in classic and modern renderings as the start of the tail, east of the Circlet of Pisces, a near-circle which forms all but the tail (the head and body) of the western (fatter) "fish" in the constellation of two fishes. Right ascension Considering stars with Flamsteed numbers, Greek letters, and proper names, Omega Piscium at J2000 (namely in the year 2000) was the named star with the highest right ascensio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iota Piscium
Iota Piscium (Iota Psc, ι Piscium, ι Psc) is single, F-type main-sequence star located 45 light years from Earth, in the constellation Pisces. Its spectral type is F7V, which means that it is somewhat larger and brighter than the Sun, but still within the range considered to have the potential for Earth-like planets. It has a surface temperature of about 6,000 to 7,500 K. Iota Piscium is suspected to be a variable star, and was once thought to have one or two stellar companions, but both are line-of-sight coincidences. It displays a far-infrared excess at a wavelength of 70μm, suggesting it is being orbited by a cold debris disk. Naming In Chinese, (), meaning ''Thunderbolt'', refers to an asterism consisting of ι Piscium, β Piscium, γ Piscium, θ Piscium, and ω Piscium. Consequently, the Chinese name Chinese names or Chinese personal names are names used by individuals from Greater China and other parts of the Chinese-speaking world throu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamma Piscium
Gamma Piscium (Gamma Psc, γ Piscium, γ Psc) is a star approximately 138 light years away from Earth, in the zodiac constellation of Pisces. It is a yellow star with a spectral type of G8 III, meaning it has a surface temperature of 4,833 K and is a giant star. It is slightly cooler than the Sun, yet it is 11 solar radii in size and shines with the light of 63 Suns. At an apparent magnitude of 3.7, it is the second brightest star in the constellation Pisces, between Eta and Alpha. Once a white A2 star, it is 5.5 billion years old. Gamma Piscium moves across the sky at three-quarters of an arcsecond per year, which at 138 light years corresponds to 153 kilometers per second. This suggests it is a visitor from another part of the Milky Way Galaxy; in astronomical terms, it will quickly leave the vicinity of the Sun. Its metallicity is only one-fourth that of the Sun, and visitors from outside the thin disk that composes the Milky Way tend to be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beta Piscium
Beta Piscium or β Piscium, formally named Fumalsamakah , is a blue-white hued star in the zodiac constellation of Pisces. Its apparent magnitude is 4.40, meaning it can be faintly seen with the naked eye. Based on parallax measurements taken during the Hipparcos mission, it is about 410 light-years (125 parsecs) distant from the Sun. Nomenclature ''β Piscium'' ( Latinised to ''Beta Piscium'') is the star's Bayer designation. It bore the traditional name ''Fum al Samakah'' from the Arabic فم السمكة ''fum al-samakah'' "mouth of the fish" (compare Fomalhaut). In 2016, the IAU organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN approved the name ''Fumalsamakah'' for this star on 1 June 2018 and it is now so included in the List of IAU-approved Star Names. In Chinese, (), meaning ''Thunderbolt'', refers to an asterism consisting of Beta Piscium and Gamma, Theta, Iota and Omega Piscium. Consequentl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wall (Chinese Constellation)
The Wall mansion () is one of the Twenty-eight mansions of the Chinese constellations. It is one of the northern mansions of the Black Tortoise The Black Tortoise () is one of the Four Symbols of the Chinese constellations. Despite its English name, it is usually depicted as a tortoise entwined together with a snake. The name used in East Asian languages does not mention either anima .... Asterisms {{Chinese constellation Chinese constellations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chinese Astronomy
Astronomy in China has a long history stretching from the Shang dynasty, being refined over a period of more than 3,000 years. The ancient Chinese people have identified stars from 1300 BCE, as Chinese star names later categorized in the twenty-eight mansions have been found on oracle bones unearthed at Anyang, dating back to the mid-Shang dynasty. The core of the "mansion" (宿 ''xiù'') system also took shape around this period, by the time of King Wu Ding (1250–1192 BCE). Detailed records of astronomical observations began during the Warring States period (fourth century BCE) and flourished from the Han period onward. Chinese astronomy was equatorial, centered on close observation of circumpolar stars, and was based on different principles from those in traditional Western astronomy, where heliacal risings and settings of zodiac constellations formed the basic ecliptic framework. Joseph Needham has described the ancient Chinese as the most persistent and accurate obser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Effective Temperature
The effective temperature of a body such as a star or planet is the temperature of a black body that would emit the same total amount of electromagnetic radiation. Effective temperature is often used as an estimate of a body's surface temperature when the body's emissivity curve (as a function of wavelength) is not known. When the star's or planet's net emissivity in the relevant wavelength band is less than unity (less than that of a black body), the actual temperature of the body will be higher than the effective temperature. The net emissivity may be low due to surface or atmospheric properties, including greenhouse effect. Star The effective temperature of a star is the temperature of a black body with the same luminosity per ''surface area'' () as the star and is defined according to the Stefan–Boltzmann law . Notice that the total (bolometric) luminosity of a star is then , where is the stellar radius. The definition of the stellar radius is obviously not straightf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
