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γ Trianguli
Gamma Trianguli (Gamma Tri, γ Trianguli, γ Tri) is a star in the constellation Triangulum located approximately 112 light years from Earth. It has an apparent magnitude of +4.01 and forms an optical (line-of-sight) triple with Delta Trianguli and 7 Trianguli. Properties This star has a stellar classification of A1Vnn, which indicates it is an A-type main sequence star. It has 2.7 times the mass of the Sun and nearly double the Sun's radius. Gamma Trianguli is radiating about 33 times the luminosity of the Sun from its outer envelope at an effective temperature of 9,440 K, giving the star a white hue. The star is roughly 300 million years old. Rotation It is rotating rapidly, with a projected rotational velocity of 254 km/s along the equator, which causes the star to take the pronounced shape of an oblate spheroid like Altair. Because the inclination of the star's axial tilt is unknown, this means that the azimuthal equatorial velocity is at leas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triangulum
Triangulum is a small constellation in the northern sky. Its name is Latin for "triangle", derived from its three brightest stars, which form a long and narrow triangle. Known to the ancient Babylonians and Greeks, Triangulum was one of the 48 constellations listed by the 2nd century astronomer Ptolemy. The celestial cartographers Johann Bayer and John Flamsteed catalogued the constellation's stars, giving six of them Bayer designations. The white stars Beta Trianguli, Beta and Gamma Trianguli, of apparent magnitudes 3.00 and 4.00, respectively, form the base of the triangle and the yellow-white Alpha Trianguli, of magnitude 3.41, the apex. Iota Trianguli is a notable double star system, and there are three star systems with known exoplanet, planets located in Triangulum. The constellation contains several galaxies, the brightest and nearest of which is the Triangulum Galaxy or Messier 33—a member of the Local Group. The first quasar ever observed, 3C 48, also lies within the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Axial Tilt
In astronomy, axial tilt, also known as obliquity, is the angle between an object's rotational axis and its orbital axis, which is the line perpendicular to its orbital plane; equivalently, it is the angle between its equatorial plane and orbital plane. It differs from orbital inclination. At an obliquity of 0 degrees, the two axes point in the same direction; that is, the rotational axis is perpendicular to the orbital plane. The rotational axis of Earth, for example, is the imaginary line that passes through both the North Pole and South Pole, whereas the Earth's orbital axis is the line perpendicular to the imaginary plane through which the Earth moves as it revolves around the Sun; the Earth's obliquity or axial tilt is the angle between these two lines. Over the course of an orbital period, the obliquity usually does not change considerably, and the orientation of the axis remains the same relative to the background of stars. This causes one pole to be pointed mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Upsilon Andromedae
Upsilon Andromedae (υ Andromedae, abbreviated Upsilon And, υ And) is a binary star located 44 light-years from Earth in the constellation of Andromeda. The system consists of an F-type main-sequence star (designated υ Andromedae A, officially named Titawin in the Amazigh language ) and a smaller red dwarf. , three extrasolar planets (designated Upsilon Andromedae b, c, d; named Saffar, Samh and Majriti, respectively) are believed to orbit υ Andromedae A. All three are likely to be jovian planets that are comparable in size to Jupiter. This was both the first multiple- planet system to be discovered around a main-sequence star, and the first multiple-planet system known in a multiple-star system. Nomenclature ''υ Andromedae'' ( Latinised to ''Upsilon Andromedae'') is the system's Bayer designation. Under the rules for naming objects in binary star systems, the two components are designated A and B. Under the same rules, the first planet discovered orbiting υ And ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chi Andromedae
Chi Andromedae ( Andromedae, And) is the Bayer designation for a star in the northern constellation of Andromeda. It has an apparent visual magnitude of +5.01, which is relatively faint for a naked-eye star. Based upon parallax measurements made during the Gaia mission, Chi Andromedae is located around from Earth. χ Andromedae is a member of (), meaning '' Heaven's Great General'', together with γ Andromedae, φ Persei, 51 Andromedae, 49 Andromedae, θ Andromedae, τ Andromedae, 56 Andromedae, β Trianguli, γ Trianguli and δ Trianguli. Consequently, the Chinese name for χ Andromedae itself is (, .) This is most likely a |
49 Andromedae
49 Andromedae is a star in the constellation Andromeda. ''49 Andromedae'' is the Flamsteed designation (abbreviated 49 And), though it also bears the Bayer designation A Andromedae. It is visible to the naked eye under good viewing conditions with an apparent visual magnitude of 5.269. The distance to 49 Andromedae, as determined from its annual parallax shift of , is around 333 light-years. It is drifting closer to the Sun with a heliocentric radial velocity of −11.5 km/s. With an estimated age of years, this is an aging red-clump giant star with a stellar classification of K0 III, indicating it is generating energy by helium fusion at its core. The spectrum displays "slightly strong" absorption lines of cyanogen (CN). It has 2.07 times the mass of the Sun and has expanded to 11 times the Sun's radius. The star is radiating 71 times the Sun's luminosity from its enlarged photosphere at an effective temperature of . It is spinning with a pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
51 Andromedae
51 Andromedae, abbreviated 51 And and formally named Nembus , is the 5th brightest star in the northern constellation of Andromeda, very slightly dimmer than the Andromeda Galaxy also being of 4th magnitude. It is an orange K-type giant star with an apparent magnitude of +3.57 and is about 169 light-years from the Earth/solar system. It is traditionally depicted as one of the two northern, far upper ends of the mythological, chained-to-the-rocks princess, the other being binary star system Gamma Andromedae. At an estimated age of 1.7 billion years, this is an evolved red giant star with a stellar classification of . The suffix notation indicates a mild enhancement of cyanogen absorption lines in its spectrum. This star has 1.8 times the mass of the Sun and it has expanded to 21.3 times the Sun's radius. It is radiating 142 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,951 K. Nomenclature ''51 Andromedae'' is the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phi Persei
Phi Persei (Phi Per, φ Persei, φ Per) is a Stellar classification, class B2Vep fourth-magnitude star in the constellation Perseus (constellation), Perseus, location about 720 light-years from Earth. System Phi Persei is spectroscopic binary consisting of a blue main sequence primary of class B2 and a Subdwarf B star, hot subdwarf secondary. The two stars have an orbit of 217 days and are separated by about . Phi Persei is a runaway star and extrapolating its space velocity (astronomy), space velocity backwards by the modelled age of the system (57 million years) places it within the Alpha Persei cluster. The primary star rotates rapidly with a projected equatorial velocity of . Due to its rapid rotation, the primary star has a polar radius about and an equatorial radius of about . With an effective temperature of nearly , it has a bolometric luminosity nearly 15,000 times higher than the Sun. The rapidly-spinning star is surrounded by a circumstel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamma Andromedae
Gamma Andromedae is a multiple star system in the northern constellation of Andromeda. It is the third-brightest star in the constellation, after Alpheratz and Mirach. Its identifier is a Bayer designation that is Latinized from γ Andromedae, and is abbreviated Gam1 And or γ1 And, respectively. The system has the proper name Almach, pronounced . Based on parallax measurements, it is estimated to be about 390 light-years distant. The system is drifting closer to the Sun with a radial velocity of . Observation In 1778, German physicist Johann Tobias Mayer discovered that γ Andromedae is a double star. When examined in a small telescope, it appears to be a bright, golden-yellow star next to a dimmer, indigo-blue star, separated by approximately 10 arcseconds. The pair is often considered by stargazers to be a beautiful double star with a striking contrast of color. The brighter member, γ1 Andromedae, is the primary of the system, and is th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bond (Chinese Constellation)
''Leu'' (or ''Low'') ''sieu'' () meaning "the Train of a garment", is one of the Twenty-eight mansions, twenty-eight lunar mansions of traditional Chinese astronomy. It is one of the mansions of the White Tiger (Chinese constellation), White Tiger of the West (西方白虎). The asterisms in the Region of ''Leu'' （婁宿天區） Notes See also * Traditional Chinese star names References * * 大崎正次 (1987). 『中国の星座の歴史』 雄山閣出版. External links * 陳冠中, 陳輝「中國古代的星象系統 (71)： 婁宿天區」 - 天文教育資訊網 (AEEA) {{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] |
Astronomical Unit
The astronomical unit (symbol: au or AU) is a unit of length defined to be exactly equal to . Historically, the astronomical unit was conceived as the average Earth-Sun distance (the average of Earth's aphelion and perihelion), before its modern redefinition in 2012. The astronomical unit is used primarily for measuring distances within the Solar System or around other stars. It is also a fundamental component in the definition of another unit of astronomical length, the parsec. One au is approximately equivalent to 499 light-seconds. History of symbol usage A variety of unit symbols and abbreviations have been in use for the astronomical unit. In a 1976 resolution, the International Astronomical Union (IAU) had used the symbol ''A'' to denote a length equal to the astronomical unit. In the astronomical literature, the symbol AU is common. In 2006, the International Bureau of Weights and Measures (BIPM) had recommended ua as the symbol for the unit, from the French ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arcsecond
A minute of arc, arcminute (abbreviated as arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of a degree. Since one degree is of a turn, or complete rotation, one arcminute is of a turn. The nautical mile (nmi) was originally defined as the arc length of a minute of latitude on a spherical Earth, so the actual Earth's circumference is very near . A minute of arc is of a radian. A second of arc, arcsecond (abbreviated as arcsec), or arc second, denoted by the symbol , is a unit of angular measurement equal to of a minute of arc, of a degree, of a turn, and (about ) of a radian. These units originated in Babylonian astronomy as sexagesimal (base 60) subdivisions of the degree; they are used in fields that involve very small angles, such as astronomy, optometry, ophthalmology, optics, navigation, land surveying, and marksmanship. To express even smaller angles, standard SI prefixes can be employed; the milliarcse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
