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Eta Cancri
Eta Cancri, Latinized from η Cancri, is a single, orange-hued star in the zodiac constellation of Cancer. It is a faint star but visible to the naked eye with an apparent visual magnitude of 5.34. The annual parallax shift of 10.93 mas as seen from Earth yields a distance estimate of 155 light years from the Sun. It is moving further away with a radial velocity of +22 km/s. A stellar classification of K3 III for Eta Cancri indicates that, at the estimated age of 3.9 billion years old, it has left the main sequence and become an evolved giant star. The spectrum shows unusually strong absorption lines of cyanogen. It has 1.5 times the mass of the Sun and has expanded to 17 times the Sun's radius. The star is radiating 87 times the Sun's luminosity from its photosphere at an effective temperature of around 4,415 K. In Chinese astronomy, ''Ghost'' () refers to an asterism consisting of Theta Cancri, Eta Cancri, Gamma Cancri and Delta Cancri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cancer (constellation)
Cancer is one of the twelve constellations of the zodiac and is located in the Northern celestial hemisphere. Its old astronomical symbol is (♋︎). Its name is Latin for crab and it is commonly represented as one. Cancer is a medium-size constellation with an area of 506 square degrees and its stars are rather faint, its brightest star Beta Cancri having an apparent magnitude of 3.5. It contains two stars with known planets, including 55 Cancri, which has five: one super-earth and four gas giants, one of which is in the habitable zone and as such has expected temperatures similar to Earth. At the (angular) heart of this sector of our celestial sphere is Praesepe (Messier 44), one of the closest open clusters to Earth and a popular target for amateur astronomers. Characteristics Cancer is a medium-sized constellation that is bordered by Gemini to the west, Lynx to the north, Leo Minor to the northeast, Leo to the east, Hydra to the south, and Canis Minor to the southwe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanogen
Cyanogen is the chemical compound with the formula ( C N)2. It is a colorless and highly toxic gas with a pungent odor. The molecule is a pseudohalogen. Cyanogen molecules consist of two CN groups – analogous to diatomic halogen molecules, such as Cl2, but far less oxidizing. The two cyano groups are bonded together at their carbon atoms: N≡C‒ C≡N, although other isomers have been detected. The name is also used for the CN radical, and hence is used for compounds such as cyanogen bromide (NCBr) (but see also ''Cyano radical''.) Cyanogen is the anhydride of oxamide: :H2NC(O)C(O)NH2 → NCCN + 2 H2O although oxamide is manufactured from cyanogen by hydrolysis: :NCCN + 2 H2O → H2NC(O)C(O)NH2 Preparation Cyanogen is typically generated from cyanide compounds. One laboratory method entails thermal decomposition of mercuric cyanide: :2 Hg(CN)2 → (CN)2 + Hg2(CN)2 Alternatively, one can combine solutions of copper(II) salts (such as copper(II) sulfate) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bayer Objects
Bayer AG (, commonly pronounced ; ) is a German multinational pharmaceutical and biotechnology company and one of the largest pharmaceutical companies in the world. Headquartered in Leverkusen, Bayer's areas of business include pharmaceuticals; consumer healthcare products, agricultural chemicals, seeds and biotechnology products. The company is a component of the Euro Stoxx 50 stock market index. Bayer was founded in 1863 in Barmen as a partnership between dye salesman Friedrich Bayer and dyer Friedrich Weskott. As was common in this era, the company was established as a dyestuffs producer. The versatility of aniline chemistry led Bayer to expand their business into other areas, and in 1899 Bayer launched the compound acetylsalicylic acid under the trademarked name Aspirin. In 1904 Bayer received a trademark for the "Bayer Cross" logo, which was subsequently stamped onto each aspirin tablet, creating an iconic product that is still sold by Bayer. Other commonly known produ ... [...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] |
Delta Cancri
Delta Cancri (δ Cancri, abbreviated Delta Cnc, δ Cnc) is a double star about 180 light-years from the Sun in the constellation of Cancer. Its two main constituents are designated Delta Cancri A and B. A is itself a binary star whose components are Delta Cancri Aa (formally named Asellus Australis , the traditional name of the entire system) and Ab. The star system is 0.08 degree north of the ecliptic, so it can be occulted by the Moon and more rarely by planets; it is occulted (eclipsed) by the sun from about 31 July to 2 August. Thus the star can be viewed the whole night, crossing the sky at the start of February. Nomenclature ''δ Cancri'' ( Latinised to ''Delta Cancri'') is the system's Bayer designation. The designations of the two constituents ''Delta Cancri A'' and ''B'', and those of ''A's'' components - ''Delta Cancri Aa'' and ''Ab'' - derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamma Cancri
Gamma Cancri, or γ Cancri, is a star in the northern constellation of Cancer. It is formally named Asellus Borealis , the traditional name of the system. Based on parallax measurements, it is located at a distance of approximately 181 light years from the Sun. The star is drifting further away with a radial velocity of 29 km/s. In 1910 this star was reported to be a spectroscopic binary by O. J. Lee, but is now considered a single star. Since it is near the ecliptic, it can be occulted by the Moon and, very rarely, by planets. Nomenclature ''γ Cancri'' ( Latinised to ''Gamma Cancri'') is the star's Bayer designation. It bore the traditional name ''Asellus Borealis'' (Latin for "northern donkey"). In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalogue and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems. It approved the name ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theta Cancri
Theta Cancri, Latinised from θ Cancri, is a multiple star system in the zodiac constellation of Cancer. It is visible to the naked eye as a dim point of light with an apparent visual magnitude of +5.32. The system is located at a distance of approximately 450 light-years away from the Sun, based on parallax, and is drifting further away with a radial velocity of +44 km/s. Since it is near the ecliptic, it can be occulted by the Moon and, very rarely, by planets. The primary, designated component A, is K-type giant star with a stellar classification of K5 III, having exhausted the supply of hydrogen at its core, then cooled and expanded. At present it has 40 times the girth of the Sun. It is radiating 353 times the luminosity of the Sun at an effective temperature of . In Chinese astronomy, ''Ghost'' () refers to an asterism consisting of Theta Cancri, Eta Cancri, Gamma Cancri and Delta Cancri Delta Cancri (δ Cancri, abbreviated Delta Cnc, δ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asterism (astronomy)
An asterism is an observed pattern or group of stars in the sky. Asterisms can be any identified pattern or group of stars, and therefore are a more general concept than the formally defined 88 constellations. Constellations are based on asterisms, but unlike asterisms, constellations outline and today completely divide the sky and all its celestial objects into regions around their central asterisms. For example, the asterism known as the Big Dipper comprises the seven brightest stars in the constellation Ursa Major. Another is the asterism of the Southern Cross, within the constellation of Crux. Asterisms range from simple shapes of just a few stars to more complex collections of many stars covering large portions of the sky. The stars themselves may be bright naked-eye objects or fainter, even telescopic, but they are generally all of a similar brightness to each other. The larger brighter asterisms are useful for people who are familiarizing themselves with the night sky. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ghost (Chinese Constellation)
The Ghost mansion () is one of the Twenty-eight mansions of the Chinese constellations. It is one of the southern mansions of the Vermilion Bird The Vermilion Bird ( zh, c=朱雀, p=Zhūquè) is one of the Four Symbols of the Chinese constellations. According to Wu Xing, the Taoist five elemental system, it represents the Fire element, the direction south, and the season summer correspo .... Asterisms {{DEFAULTSORT:Ghost (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] |
Photosphere
The photosphere is a star's outer shell from which light is radiated. The term itself is derived from Ancient Greek roots, φῶς, φωτός/''phos, photos'' meaning "light" and σφαῖρα/''sphaira'' meaning "sphere", in reference to it being a spherical surface that is perceived to emit light. It extends into a star's surface until the plasma becomes opaque, equivalent to an optical depth of approximately , or equivalently, a depth from which 50% of light will escape without being scattered. A photosphere is the deepest region of a luminous object, usually a star, that is transparent to photons of certain wavelengths. Temperature The surface of a star is defined to have a temperature given by the effective temperature in the Stefan–Boltzmann law. Stars, except neutron stars, have no solid or liquid surface. Therefore, the photosphere is typically used to describe the Sun's or another star's visual surface. Composition of the Sun The Sun is composed primarily of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
