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Phi Sagittarii
Phi Sagittarii, Latinized from φ Sagittarii, is a star in the southern constellation of Sagittarius. With an apparent visual magnitude of 3.17, it is the ninth-brightest star in the constellation and is readily visible to the naked eye. Parallax measurements place it at a distance of roughly from the Earth. It is receding with a radial velocity of +21.5 km/s. The stellar classification of this star has been rated at B8.5 III, with the luminosity class of III indicating it is a giant star evolved away from the main sequence after it has exhausted the hydrogen at its core. This energy is being radiated from the star's outer envelope at an effective temperature of , which produces the blue-white hue typical of B-type stars. In the past, this star catalogued as a spectroscopic binary and a companion was apparently detected through lunar occultation. However, it is most likely a solitary star and any nearby stars are merely optical companions. Name and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sagittarius (constellation)
Sagittarius is one of the constellations of the zodiac and is located in the Southern celestial hemisphere. It is one of the 48 constellations listed by the 2nd-century astronomer Ptolemy and remains one of the 88 modern constellations. Its old astronomical symbol is (♐︎). Its name is Latin for "archer". Sagittarius is commonly represented as a centaur pulling back a bow. It lies between Scorpius and Ophiuchus to the west and Capricornus and Microscopium to the east. The center of the Milky Way lies in the westernmost part of Sagittarius (see Sagittarius A). Visualizations As seen from the northern hemisphere, the constellation's brighter stars form an easily recognizable asterism known as "the Teapot". The stars δ Sgr (Kaus Media), ε Sgr (Kaus Australis), ζ Sgr (Ascella), and φ Sgr form the body of the pot; λ Sgr (Kaus Borealis) is the point of the lid; γ2 Sgr (Alnasl) is the tip of the spout; and σ Sgr (Nunki) and τ Sgr the handle. These ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Occultation
An occultation is an event that occurs when one object is hidden from the observer by another object that passes between them. The term is often used in astronomy, but can also refer to any situation in which an object in the foreground blocks from view (occults) an object in the background. In this general sense, occultation applies to the visual scene observed from low-flying aircraft (or computer-generated imagery) when foreground objects obscure distant objects dynamically, as the scene changes over time. If the closer body does not entirely conceal the farther one, the event is called a '' transit''. Both transit and occultation may be referred to generally as ''occlusion''; and if a shadow is cast onto the observer, it is called an eclipse. The symbol for an occultation, and especially a solar eclipse, is file:Occultation symbol.svg (U+1F775 🝵). Occultations by the Moon The term occultation is most frequently used to describe lunar occultations, those relativ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta Sagittarii
Delta Sagittarii (δ Sagittarii, abbreviated Delta Sgr, δ Sgr), formally named Kaus Media , is a double star in the southern zodiac constellation of Sagittarius. The apparent visual magnitude of this star is +2.70, making it easily visible to the naked eye. Parallax measurements place the distance at roughly from the Sun. Properties Eggleton and Tokovinin (2008) list Delta Sagittarii as a binary star system consisting of an evolved K-type giant star with a stellar classification of K3 III, and a white dwarf companion. The giant is a weak barium star, most likely having had its surface abundance of s-process elements enhanced through mass transfer from its orbiting companion. It has an estimated 3.21 times the mass of the Sun and is about 260million years old. Delta Sagittarii has three dim visual companions: * a 14th magnitude star at a separation of 26 arcseconds, * a 15th magnitude star at a separation of 40 arcseconds, and * a 13th magnitude s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamma Sagittarii
The Bayer designation γ Sagittarii (Gamma Sagittarii) is shared by two stars in the constellation Sagittarius: * γ1 Sagittarii, a Cepheid variable better-known as W Sagittarii W Sagittarii (W Sgr, Gamma-1 Sagittarii (γ¹ Sgr)) is a multiple star system star in the constellation Sagittarius, and a Cepheid variable star. W Sagittarii is an optical line-of-sight companion nearly a degree from the much ... * γ2 Sagittarii (10 Sagittarii), an orange giant * "-": none The two stars are separated by slightly under one degree. References {{Set index article , astronomical objects Sagittarius, Gamma Sagittarius (constellation) ... [...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 K� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zeta Sagittarii
Zeta Sagittarii (ζ Sagittarii, abbreviated Zeta Sgr, ζ Sgr) is a triple star system and the third-brightest star in the constellation of Sagittarius. Based upon parallax measurements, it is about from the Sun. The three components are designated Zeta Sagittarii A (officially named Ascella , the traditional name for the entire system) and B, themselves forming a binary pair, and a smaller companion star, C. Nomenclature ''ζ Sagittarii'' ( Latinised to ''Zeta Sagittarii'') is the system's Bayer designation. The designations of the two components as ''ζ Sagittarii A'', ''B'' and ''C'' derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU). It bore the traditional name ''Ascella'', from a Late Latin word meaning ''armpit''. In the catalogue of stars in the ''Calendarium'' of Al Achsasi al Mouakket, this star was designated ''Thalath al Sadirah ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tau Sagittarii
Tau Sagittarii (Tau Sgr, τ Sagittarii, τ Sgr) is a star in the southern zodiac constellation of Sagittarius. Description With an apparent visual magnitude of +3.3, this is one of the brighter members of the constellation. The distance of this star from Earth is roughly , based upon parallax measurements. This is a spectral type K1 giant star with about . The stellar envelope is slightly cooler than the Sun with an effective temperature of 4,459 K, giving the star a light orange color. The interferometry-measured angular diameter of this star, after correcting for limb darkening, is , which, at its estimated distance, equates to a physical radius of about 16 times the radius of the Sun. τ Sagittarii is a suspected double star although no companion has been confirmed yet. A lower metal content (Fe to H ratio is 54% lower than the sun's) and a high peculiar velocity (64 km/s, four times the local average) relative to the Sun suggest the star is a vi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sigma Sagittarii
Sigma Sagittarii, Latinized from σ Sagittarii; formally named Nunki , is the second-brightest star in the constellation of Sagittarius. It has an apparent magnitude of +2.05, making it readily visible to the naked eye. The distance to this star, determined using parallax measurements from the Hipparcos astrometry satellite, yields a value of approximately from the Sun. Properties Sigma Sagittarii has a spectrum matching a stellar classification of B2.5 V, which indicates this is a B-type main-sequence star. Its total luminosity is 3300 times that of the Sun while it has a surface temperature of 18,890 K. X-ray emission has been detected from this star, which has an estimated X-ray luminosity of . It has a 10th magnitude optical companion located 5.2 arcminutes away. It is 3.45 degrees south of the ecliptic, so it can be occulted by the Moon and rarely by planets. The last occultation by a planet took place on November 17, 1981, when it was occulted b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mu Sagittarii
Mu Sagittarii (μ Sagittarii, abbreviated Mu Sgr, μ Sgr) is a multiple star system in the constellation of Sagittarius. The brightest component, designated Mu Sagittarii Aa, is formally named Polis . The system is 3,000 light-years from the Sun and is part of the Sgr OB1 stellar association. System The components of the Mu Sagittarii system are designated 'A' through 'E', in order of their distance from the brightest, which is Mu Sagittarii A. 'A' is itself a spectroscopic binary with components designated Mu Sagittarii Aa and Ab. Of the five visible stars, component C is considered an optical double, not physically close to the other stars. Component D has also been listed as a purely optical double by some authors, but others consider it to be part of a trapezium system of four gravitationally bound stars (plus an unseen companion). Nomenclature ''μ Sagittarii'' ( Latinised to ''Mu Sagittarii'') is the system's Bayer designation. The desig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lambda Sagittarii
Lambda Sagittarii ( Latinized from λ Sagittarii), formally named Kaus Borealis , is a star in the southern constellation of Sagittarius. The star marks the top of the Archer's bow. Properties With an apparent visual magnitude of +2.82, this is one of the brighter members of the constellation and, according to the Bortle Dark-Sky Scale, it is readily visible to the naked eye. Based upon parallax measurements, it is from the Sun. Being 2.1 degrees south of the ecliptic, Lambda Sgr is sometimes occulted by the Moon and, rarely, by a planet. The last planet to pass in front of it was Venus, on 19 November 1984. The previous occasion was 5 December 1865, when it was occulted by Mercury. Kaus Borealis is a subgiant star with a stellar classification of K0 IV. It has a mass 2.6 times that of the Sun and a physical size of about 11.2 times the Sun's radius. This expanded outer envelope is radiating energy at an effective temperature of 4,770 K, causing it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dipper (Chinese Constellation)
The Dipper mansion (斗宿, pinyin: Dǒu Xiù) is one of the Twenty-eight mansions of the Chinese constellations. It is one of the northern mansions of the Black Tortoise. In Taoism, it is known as the "Six Stars of the Southern Dipper" (南斗六星, Nándǒu liù xīng), in contrast to the Big Dipper The Big Dipper ( US, Canada) or the Plough ( UK, Ireland) is a large asterism consisting of seven bright stars of the constellation Ursa Major; six of them are of second magnitude and one, Megrez (δ), of third magnitude. Four define a "bowl" ... north to this mansion. Asterisms Stars * ζ Sgr * τ Sgr * σ Sgr * φ Sgr * λ Sgr * μ Sgr {{DEFAULTSORT:Dipper (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 o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
