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Mu Aquarii
Mu Aquarii, Latinized from μ Aquarii, is the Bayer designation for a binary star system in the equatorial constellation of Aquarius. It 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. The primary has an estimated 3.5 times the Sun's radius and is radiating 26 times the luminosity of the Sun from its photosphere at an effective temperature of 6,906 km/s. This star together with ... [...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 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 (constellation), 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 commonly depic ... [...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, 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 Ca (and/or Sc) and/or an apparent overabundance of the 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. This leads to two or three spectral types being given. For example, Sirius has been given a spectral type of kA0hA0VmA1, indicating that it is A0 when judged by the Calcium k line, A0V when judged by its hydrogen lines, and A1 when judged by the lines of heavy metals. There are othe ... [...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 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 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 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] |
Nu Aquarii
Nu Aquarii (ν Aqr, ν Aquarii) is the Bayer designation for a star in the equatorial constellation of Aquarius. With an apparent visual magnitude of 4.52, Nu Aquarii is visible to the naked eye. Its distance from Earth, as determined from parallax measurements, is around . At an estimated age of 708 million years, it has evolved into a giant star with a spectrum that matches a stellar classification of G8 III. It has than double the mass of the Sun and has expanded to eight times the Sun's radius. Nu Aquarii is radiating 37-fold the luminosity of the Sun from its outer atmosphere 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-bulaʽān'' (''ألبولعان''), meaning "the two swallowers". This star, along with ε Aqr (Albali) and μ Aqr (Albulaan), were ''al Bulaʽ'' (''البلع'')—the Swallower. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epsilon Aquarii
Epsilon Aquarii, Latinized from ε Aquarii, is a single star in the equatorial zodiac constellation of Aquarius, located near the western constellation border with Capricornus. It has the proper name Albali , now formally recognized by the IAU. This is a white-hued star that is visible to the naked eye with an apparent visual magnitude of 3.77. Based upon parallax measurements taken during the Hipparcos mission, it is located at a distance of approximately from the Sun with an absolute magnitude of −0.46. The star is drifting closer with a radial velocity of −15 km/s. This object is an A-type main-sequence star with a stellar classification of A1 V. It is an estimated 388 million years old with a high rate of spin, showing a projected rotational velocity of around 118 km/s. The elemental abundances in the stellar atmosphere are close to solar, with pronounced underabundances of aluminium and strontium. The star has three times the mass of the Sun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arabic Language
Arabic (, ' ; , ' or ) is a Semitic language spoken primarily across the Arab world.Semitic languages: an international handbook / edited by Stefan Weninger; in collaboration with Geoffrey Khan, Michael P. Streck, Janet C. E.Watson; Walter de Gruyter GmbH & Co. KG, Berlin/Boston, 2011. Having emerged in the 1st century, it is named after the Arab people; the term "Arab" was initially used to describe those living in the Arabian Peninsula, as perceived by geographers from ancient Greece. Since the 7th century, Arabic has been characterized by diglossia, with an opposition between a standard prestige language—i.e., Literary Arabic: Modern Standard Arabic (MSA) or Classical Arabic—and diverse vernacular varieties, which serve as mother tongues. Colloquial dialects vary significantly from MSA, impeding mutual intelligibility. MSA is only acquired through formal education and is not spoken natively. It is the language of literature, official documents, and formal written m ... [...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 Semitic languages, Semitic language spoken primarily across the Arab world.Semitic languages: an international handbook / edited by Stefan Weninger; in collaboration with Geoffrey Khan, Michael P. Streck, Janet C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ν Aquarii
Nu Aquarii (ν Aqr, ν Aquarii) is the Bayer designation for a star in the equatorial constellation of Aquarius. With an apparent visual magnitude of 4.52, Nu Aquarii is visible to the naked eye. Its distance from Earth, as determined from parallax measurements, is around . At an estimated age of 708 million years, it has evolved into a giant star with a spectrum that matches a stellar classification of G8 III. It has than double the mass of the Sun and has expanded to eight times the Sun's radius. Nu Aquarii is radiating 37-fold the luminosity of the Sun from its outer atmosphere 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-bulaʽān'' (''ألبولعان''), meaning "the two swallowers". This star, along with ε Aqr (Albali) and μ Aqr (Albulaan), were ''al Bulaʽ'' (''البلع'')—the Swallower. In Chinese ... [...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] |
