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Zeta Apodis
Zeta Apodis, Latinized from ζ Apodis, is the Bayer designation for a star in the southern constellation of Apus. It has an apparent visual magnitude of +4.78, which is bright enough to allow it to be seen with the naked eye. The distance to this star is known from parallax measurements to be around . The spectrum of Zeta Apodis matches a stellar classification of K2 III, with the luminosity class of III indicating it is an evolved giant star. The measured angular diameter of this star, after correction for limb darkening, is . At the estimated distance of Eta Draconis, this yields a physical size of about 11 times the radius of the Sun. The outer atmosphere has an effective temperature of 4,388 K, which gives it the orange-hued glow of a K-type star. Naming In Chinese Chinese can refer to: * Something related to China * Chinese people, people of Chinese nationality, citizenship, and/or ethnicity **''Zhonghua minzu'', the supra-ethnic concept of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apus IAU
Apus is a small constellation in the Southern Celestial Hemisphere, southern sky. It represents a bird-of-paradise, and its name means "without feet" in Greek language, Greek because the bird-of-paradise was once wrongly believed to lack feet. First depicted on a celestial globe by Petrus Plancius in 1598, it was charted on a star atlas by Johann Bayer in his 1603 ''Uranometria''. The French explorer and astronomer Nicolas Louis de Lacaille charted and gave the brighter stars their Bayer designations in 1756. The five brightest stars are all reddish in hue. Shading the others at apparent magnitude 3.8 is Alpha Apodis, an orange giant that has around 48 times the diameter and 928 times the luminosity of the Sun. Marginally fainter is Gamma Apodis, another ageing giant star. Delta Apodis is a double star, the two components of which are 103 Minute and second of arc, arcseconds apart and visible with the naked eye. Two star systems have been found to have exoplanet, planets. Hist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angular Diameter
The angular diameter, angular size, apparent diameter, or apparent size is an angular distance describing how large a sphere or circle appears from a given point of view. In the vision sciences, it is called the visual angle, and in optics, it is the angular aperture (of a lens). The angular diameter can alternatively be thought of as the angular displacement through which an eye or camera must rotate to look from one side of an apparent circle to the opposite side. Humans can resolve with their naked eyes diameters of up to about 1 arcminute (approximately 0.017° or 0.0003 radians). This corresponds to 0.3 m at a 1 km distance, or to perceiving Venus as a disk under optimal conditions. Formula The angular diameter of a circle whose plane is perpendicular to the displacement vector between the point of view and the center of said circle can be calculated using the formula :\delta = 2\arctan \left(\frac\right), in which \delta is the angular diameter, and d is the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta Apodis
Delta Apodis (δ Aps, δ Apodis) is the Bayer designation for a double star in the southern constellation of Apus. The brighter star, δ Apodis, is an M-type red giant and has an apparent magnitude that varies from magnitude +4.66 to +4.87. It is classified as a semiregular variable with pulsations of multiple periods of 68.0, 94.9 and 101.7 days. At an angular separation of 102.9 arcseconds is δ Apodis, an orange K-type giant with an apparent magnitude of +5.27. Hipparcos data report the distance to δ Apodis to be approximately 760 light years, while δ Apodis is found to be around 610 light years from Earth. They may form a common proper motion pair. Naming In Chinese Chinese can refer to: * Something related to China * Chinese people, people of Chinese nationality, citizenship, and/or ethnicity **''Zhonghua minzu'', the supra-ethnic concept of the Chinese nation ** List of ethnic groups in China, people of ... caused by adaptation of the European sout ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta Octantis
δ Octantis, Latinised as Delta Octantis, has the distinction of being Saturn's southern pole star. An orange giant of class K2III, it has 1.2 times the mass of the Sun and about 25 times the Sun's radius. This star is about 4.3 billion years old, which is similar to the age of the Sun. Naming In Chinese Chinese can refer to: * Something related to China * Chinese people, people of Chinese nationality, citizenship, and/or ethnicity **''Zhonghua minzu'', the supra-ethnic concept of the Chinese nation ** List of ethnic groups in China, people of ... caused by adaptation of the European southern hemisphere constellations into the Chinese system, (), meaning '' Exotic Bird'', refers to an asterism consisting of δ Octantis, ζ Apodis, ι Apodis, β Apodis, γ Apodis, δ1 Apodis, η Apodis, α Apodis and ε Apodis. Consequently, δ Octantis itself is known as (, en, the Fifth Star of Exotic Bird). References Octans Octantis, Delta CD-83 189 070638 5 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamma Apodis
Gamma Apodis (γ Aps, γ Apodis) is the Bayer designation for a star in the southern circumpolar constellation of Apus. From parallax measurements, the distance to this star can be estimated as . It is visible to the naked eye with an apparent visual magnitude of 3.86. A stellar classification of G9 III identifies it as a giant star in the later stages of its evolution. It is an active X-ray source with a luminosity of , making it one of the 100 strongest stellar X-ray sources within 50 parsecs of the Sun. Naming In Chinese Chinese can refer to: * Something related to China * Chinese people, people of Chinese nationality, citizenship, and/or ethnicity **''Zhonghua minzu'', the supra-ethnic concept of the Chinese nation ** List of ethnic groups in China, people of ... caused by adaptation of the European southern hemisphere constellations into the Chinese system, (), meaning '' Exotic Bird'', refers to an asterism consisting of γ Apodis, ζ Apodis, ι Apo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beta Apodis
Beta Apodis (β Aps, β Apodis) is the Bayer designation for a star in the southern circumpolar constellation of Apus. It is located approximately from Earth, as determined by parallax measurements. The apparent visual magnitude of this star is +4.24, which is bright enough to be seen with the naked eye The spectrum of this star matches the characteristics of a K0 III, which, according to models of stellar evolution, indicates that it is in the giant star stage, having exhausted the supply of hydrogen at its core. The measured angular diameter of this star is . At the estimated distance of this star, this yields a physical size of about 11 times the radius of the Sun. The expanded outer atmosphere of Beta Apodis has an effective temperature of about 4,900 K. This heat is causing it to glow with the characteristic orange hue of a K-type star. Naming In Chinese Chinese can refer to: * Something related to China * Chinese people, people of Chinese natio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iota Apodis
Iota Apodis (ι Aps, ι Apodis) is the Bayer designation for a binary star system in the southern circumpolar constellation of Apus. It is a faint target at an apparent visual magnitude of 5.41, but still visible to the naked eye from suitably dark skies. The distance to this star can be roughly gauged from parallax measurements, yielding an estimate of with a 20% margin of error. Both stars are B-type main sequence stars, which indicates they shine with a blue-white hue. The brighter component has a stellar classification of B9 V and an apparent magnitude 5.90, while the second member is a B9.5 V star with a magnitude of 6.46. The pair have an angular separation of 0.091 arcseconds with an estimated orbital period of 59.32 years. They are about 3.89 and 3.45 times as massive as the Sun. Naming In Chinese Chinese can refer to: * Something related to China * Chinese people, people of Chinese nationality, citizenship, and/or ethnicity **''Zh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chinese Constellations
Traditional Chinese astronomy has a system of dividing the celestial sphere into asterisms or constellations, known as "officials" (Chinese ''xīng guān''). The Chinese asterisms are generally smaller than the constellations of Hellenistic tradition. The Song dynasty (13th-century) Suzhou planisphere shows a total of 283 asterisms, comprising a total of 1,565 individual stars. The asterisms are divided into four groups, the Twenty-Eight Mansions (, ''Èrshíbā Xiù'') along the ecliptic, and the Three Enclosures of the northern sky. The southern sky was added as a fifth group in the late Ming Dynasty based on European star charts, comprising an additional 23 asterisms. The Three Enclosures (, ''Sān Yuán'') include the Purple Forbidden Enclosure, which is centered on the north celestial pole and includes those stars which could be seen year-round,Needham, J.Astronomy in Ancient and Medieval China. ''Philosophical Transactions of the Royal Society of London''. Series A, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chinese Language
Chinese (, especially when referring to written Chinese) is a group of languages spoken natively by the ethnic Han Chinese majority and many minority ethnic groups in Greater China. About 1.3 billion people (or approximately 16% of the world's population) speak a variety of Chinese as their first language. Chinese languages form the Sinitic branch of the Sino-Tibetan languages family. The spoken varieties of Chinese are usually considered by native speakers to be variants of a single language. However, their lack of mutual intelligibility means they are sometimes considered separate languages in a family. Investigation of the historical relationships among the varieties of Chinese is ongoing. Currently, most classifications posit 7 to 13 main regional groups based on phonetic developments from Middle Chinese, of which the most spoken by far is Mandarin (with about 800 million speakers, or 66%), followed by Min (75 million, e.g. Southern Min), Wu (74 million, e.g. Shangh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
K-type Star
In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting the rainbow of colors interspersed with spectral lines. Each line indicates a particular chemical element or molecule, with the line strength indicating the abundance of that element. The strengths of the different spectral lines vary mainly due to the temperature of the photosphere, although in some cases there are true abundance differences. The ''spectral class'' of a star is a short code primarily summarizing the ionization state, giving an objective measure of the photosphere's temperature. Most stars are currently classified under the Morgan–Keenan (MK) system using the letters ''O'', ''B'', ''A'', ''F'', ''G'', ''K'', and ''M'', a sequence from the hottest (''O'' type) to the coolest (''M'' type). Each letter class is then subdivided ... [...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] |
Stellar Atmosphere
The stellar atmosphere is the outer region of the volume of a star, lying above the stellar core, radiation zone and convection zone. Overview The stellar atmosphere is divided into several regions of distinct character: * The photosphere, which is the atmosphere's lowest and coolest layer, is normally its only visible part. Light escaping from the surface of the star stems from this region and passes through the higher layers. The Sun's photosphere has a temperature in the 5,770 K to 5,780 K range. Starspots, cool regions of disrupted magnetic field lie on the photosphere. * Above the photosphere lies the chromosphere. This part of the atmosphere first cools down and then starts to heat up to about 10 times the temperature of the photosphere. * Above the chromosphere lies the transition region, where the temperature increases rapidly on a distance of only around 100 km. * The outermost part of the stellar atmosphere is the corona, a tenuous plasma which has a tem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
