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μ Aqr
Mu Aquarii is the for a binary star system in the equatorial constellation of Aquarius. Its name is a Bayer designation that is Latinized from μ Aquarii, and abbreviated Mu Aqr or μ Aqr. The star is visible to the naked eye with a combined apparent visual magnitude of 4.7. Based upon parallax measurements, the distance to this system is about . It is drifting closer to the Sun with a radial velocity of −9.1 km/s. This star was tentatively identified as a single-lined spectroscopic binary by Helmut A. Abt in 1961. It has an orbital period of and an eccentricity (ovalness) of 0.23. The pair have been resolved by speckle interferometry, showing an angular separation of . The visible spectrum matches a stellar classification of A3m, with the 'm' suffix indicating that this is an Am, or chemically peculiar star. A 2020 classification of , indicates ionized calcium (k) lines match a class of A4, hydrogen lines (h) a class of F1, and metal lines (m) F3. There ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquarius (constellation)
Aquarius is an celestial equator, equatorial constellation of the zodiac, between Capricornus and Pisces (constellation), Pisces. Its name is Latin for "water-carrier" or "cup-carrier", and its old astronomical symbol is (♒︎), a representation of water. Aquarius is one of the oldest of the recognized constellations along the zodiac (the Sun's apparent path). It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the IAU designated constellations, 88 modern constellations. It is found in a region often called the Sea (astronomy), Sea due to its profusion of constellations with watery associations such as Cetus the whale, Pisces the fish, and Eridanus (constellation), Eridanus the river. At apparent magnitude 2.9, Beta Aquarii is the brightest star in the constellation. History and mythology Aquarius is identified as "The Great One" in the Babylonian star catalogues and represents the god Ea (god), Ea himself, who is commonl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Am Star
An Am star or metallic-line star is a type of chemically peculiar star of spectral type A whose spectrum has strong and often variable absorption lines of metals such as zinc Zinc is a chemical element; it has symbol Zn and atomic number 30. It is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic tabl ..., strontium, zirconium, and barium, and deficiencies of others, such as calcium and scandium. The original definition of an Am star was one in which the star shows "an apparent surface underabundance of calcium, Ca (and/or scandium, Sc) and/or an apparent overabundance of the iron group, Fe group and heavier elements". The unusual relative abundances cause the spectral type assessed from the Calcium K lines to be systematically earlier than one assessed from other metallic lines. Typically, a spectral type judged solely from hydrogen lines is intermediate. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
4 Aquarii
4 Aquarii (abbreviated 4 Aqr) is a binary star system in the constellation Aquarius, located approximately 198 light years away from the Sun. ''4 Aquarii'' is the Flamsteed designation. It is visible to the naked eye as a dim, yellow-white hued star with a combined apparent visual magnitude of 5.99. The system is moving closer to the Earth with a heliocentric radial velocity of −21.5 km/s. This is a visual binary with an orbital period of 200.7 years and an eccentricity of 0.535. The magnitude 6.40 primary, designated component A, is an F-type subgiant star with a stellar classification of F7 IV, suggesting that it has exhausted the hydrogen at its core and evolved off the main sequence. It has a dynamically-measured mass 1.6 times that of the Sun and is radiating 11 times the Sun's luminosity from its photosphere at an effective temperature of 6,440 K. The magnitude 7.43 secondary, component B, is a suspected F-type main-sequence star An F-t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Girl (Chinese Constellation)
The Girl mansion (女宿, pinyin: Nǚ Xiù) is one of the Twenty-eight mansions of the Chinese constellation 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 Hellenisti ...s. It is one of the northern mansions of the Black Tortoise. Asterisms Notes {{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 China, 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). They flourished during the Han period (202 BCE – 220 CE) and subsequent dynasties with the publication of star catalogues. 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 framew ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nu Aquarii
Nu Aquarii is a star in the equatorial constellation of Aquarius. The name is a Bayer designation that is Latinized from ν Aquarii, and abbreviated Nu Aqr or ν Aqr. With an apparent visual magnitude of 4.52, Nu Aquarii is faintly visible to the naked eye. Its distance from Earth, as determined from parallax measurements, is . The star is drifting closer to the Sun with a radial velocity of −11 km/s. At an estimated age of 708 million years, Nu Aquarii has exhausted the supply of hydrogen at its core and evolved into a giant star with a spectrum that matches a stellar classification of G8 III. It has double the mass of the Sun and has expanded to eight times the Sun's radius. Nu Aquarii is radiating 37 times the luminosity of the Sun from its photosphere at an effective temperature of . At this heat, the star is glowing with the yellowish hue of a G-type star. Together with μ Aquarii, it is Albulaan , a name derived from the Arabic term ''al-bulaʽ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epsilon Aquarii
Epsilon Aquarii is a binary star system in the equatorial zodiac constellation of Aquarius, located near the western constellation border with Capricornus. Its identifier is a Bayer designation that is Latinized from ε Aquarii, and abbreviated Eps Aqr or ε Aqr, respectively. It has the proper name Albali , now formally recognized by the IAU. This system is visible to the naked eye as a point of light with an apparent visual magnitude of 3.77, and has an absolute magnitude of −0.46. Based upon parallax measurements taken by the Gaia spacecraft, it is located at a distance of approximately from Earth. The star is drifting closer with a radial velocity of −20 km/s. Properties The primary member has a stellar classification of A1 V, indicating it is an A-type main-sequence star. However, isochrone fitting suggests this star has recently evolved away from the main sequence and is now a subgiant star. It is estimated to be 388 million years old with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arabic Language
Arabic (, , or , ) is a Central Semitic languages, Central Semitic language of the Afroasiatic languages, Afroasiatic language family spoken primarily in the Arab world. The International Organization for Standardization (ISO) assigns language codes to 32 varieties of Arabic, including its standard form of Literary Arabic, known as Modern Standard Arabic, which is derived from Classical Arabic. This distinction exists primarily among Western linguists; Arabic speakers themselves generally do not distinguish between Modern Standard Arabic and Classical Arabic, but rather refer to both as ( "the eloquent Arabic") or simply ' (). Arabic is the List of languages by the number of countries in which they are recognized as an official language, third most widespread official language after English and French, one of six official languages of the United Nations, and the Sacred language, liturgical language of Islam. Arabic is widely taught in schools and universities around the wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albulaan term, ''al-bulaʽān'' (ألبولعان) meaning "the two swallowers".
{{Set index article , astronomical objects ...
The traditional star name Albulaan refers to two stars in the Aquarius constellation: * μ Aquarii * ν Aquarii The name derives from the Arabic Arabic (, , or , ) is a Central Semitic languages, Central Semitic language of the Afroasiatic languages, Afroasiatic language family spoken primarily in the Arab world. The International Organization for Standardization (ISO) assigns lang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ν Aquarii
Nu Aquarii is a star in the equatorial constellation of Aquarius. The name is a Bayer designation that is Latinized from ν Aquarii, and abbreviated Nu Aqr or ν Aqr. With an apparent visual magnitude of 4.52, Nu Aquarii is faintly visible to the naked eye. Its distance from Earth, as determined from parallax measurements, is . The star is drifting closer to the Sun with a radial velocity of −11 km/s. At an estimated age of 708 million years, Nu Aquarii has exhausted the supply of hydrogen at its core and evolved into a giant star with a spectrum that matches a stellar classification of G8 III. It has double the mass of the Sun and has expanded to eight times the Sun's radius. Nu Aquarii is radiating 37 times the luminosity of the Sun from its photosphere at an effective temperature of . At this heat, the star is glowing with the yellowish hue of a G-type star. Together with μ Aquarii, it is Albulaan , a name derived from the Arabic term ''al-bulaʽ ... [...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, such as the 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photosphere
The photosphere is a star's outer shell from which light is radiated. 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 region of a luminous object, usually a star, that is transparent to photons of certain wavelengths. 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. Etymology The term ''photosphere'' 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. Temperature The surface of a star is defined to have a temperature given by the effective temperature in the Stefan–Boltzmann law. Various stars have photospheres of vari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
