|
Beta Piscis Austrini
Beta Piscis Austrini, Romanization of Greek, Latinized from β Piscis Austrini, is catalogued as a binary star system in the southern constellation of Piscis Austrinus. It is visible to the naked eye with an apparent visual magnitude of +4.29. Based upon an annual parallax shift of 22.84 milliarcsecond, mas as seen from the Earth, the star is located 143 light years from the Sun. These coordinates are a source of X-ray astronomy, X-ray emission with a luminosity of , which is most likely coming from a source other than the A-type stars. Oblak (1978) identified this as a triple star system, although subsequent sources list it as a binary. The magnitude 4.29 primary, component A, is a white-hued A-type main sequence star with a stellar classification of A1 V. It has an estimated 2.3 times the mass of the Sun and 2.1 times the Sun's radius. The star is radiating 37 times the solar luminosity from its photosphere at an effective temperature of 9,638 K ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
J2000
In astronomy, an epoch or reference epoch is a instant, moment in time used as a reference point for some time-varying astronomical quantity. It is useful for the celestial coordinates or orbital elements of a Astronomical object, celestial body, as they are subject to Perturbation (astronomy), perturbations and vary with time. These time-varying astronomical quantities might include, for example, the mean longitude or mean anomaly of a body, the node of its orbit relative to a reference plane, the direction of the apogee or Perihelion and aphelion, aphelion of its orbit, or the size of the major axis of its orbit. The main use of astronomical quantities specified in this way is to calculate other relevant parameters of motion, in order to predict future positions and velocities. The applied tools of the disciplines of celestial mechanics or its subfield orbital mechanics (for predicting orbital paths and positions for bodies in motion under the gravitational effects of other bodi ... [...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] |
A-type Main-sequence Stars
A type or type A may refer to: * A-type asteroid, a type of relatively uncommon inner-belt asteroids * A type blood, a type in the ABO blood group system * A-type inclusion, a type of cell inclusion * A-type potassium channel, a type of voltage-gated potassium channel * A type proanthocyanidin, a specific type of flavonoids * A-type star, a class of stars * Type A Dolby Noise Reduction, a type of Dolby noise-reduction system * Type A climate, a type in the Köppen climate classification * Type A flu, a type of influenza virus * Type A evaluation of uncertainty, an uncertainty in measurement that can be inferred, for example, from repeated measurement * Type A (label), a music label that for example produced the 2004 album '' What Doesn't Kill You...'' by Candiria * Type A personality, a personality type in the Type A and Type B personality theory * Type A submarine, a class of submarines in the Imperial Japanese Navy which served during the Second World War * Hemophilia type A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centre De Données Astronomiques De Strasbourg
Center or centre may refer to: Mathematics *Center (geometry), the middle of an object * Center (algebra), used in various contexts ** Center (group theory) ** Center (ring theory) * Graph center, the set of all vertices of minimum eccentricity Places United States * Centre, Alabama * Center, Colorado * Center, Georgia * Center, Indiana * Center, Jay County, Indiana * Center, Warrick County, Indiana * Center, Kentucky * Center, Missouri * Center, Nebraska * Center, North Dakota * Centre County, Pennsylvania * Center, Portland, Oregon * Center, Texas * Center, Washington * Center, Outagamie County, Wisconsin * Center, Rock County, Wisconsin **Center (community), Wisconsin *Center Township (other) *Centre Township (other) *Centre Avenue (other) *Center Hill (other) Other countries * Centre region, Hainaut, Belgium * Centre Region, Burkina Faso * Centre Region (Cameroon) * Centre-Val de Loire, formerly Centre, France * Centre (department), H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monthly Notices Of The Royal Astronomical Society
''Monthly Notices of the Royal Astronomical Society'' (MNRAS) is a peer-reviewed scientific journal covering research in astronomy and astrophysics. It has been in continuous existence since 1827 and publishes letters and papers reporting original research in relevant fields. Despite the name, the journal is no longer monthly, nor does it carry the notices of the Royal Astronomical Society. History The first issue of MNRAS was published on 9 February 1827 as ''Monthly Notices of the Astronomical Society of London'' and it has been in continuous publication ever since. It took its current name from the second volume, after the Astronomical Society of London became the Royal Astronomical Society (RAS). Until 1960 it carried the monthly notices of the RAS, at which time these were transferred to the newly established ''Quarterly Journal of the Royal Astronomical Society'' (1960–1996) and then to its successor journal ''Astronomy & Geophysics'' (since 1997). Until 1965, MNRAS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Well (Chinese Constellation)
The Well mansion (井宿, pinyin: Jǐng Xiù ; Japanese: chichiri-boshi) is one of the Twenty-eight mansions of the Chinese constellations. It is one of the southern mansions of the Vermilion Bird The Vermilion Bird ( zh, c=朱雀, p=Zhūquè) is one of the Four Symbols of the Chinese constellations. According to Wu Xing, the Taoist five elemental system, it represents the Fire element, the direction south, and the season summer correspo .... Asterisms {{DEFAULTSORT:Well (Chinese Constellation) Chinese constellations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and borders fourteen countries by land, the most of any country in the world, tied with Russia. Covering an area of approximately , it is the world's third largest country by total land area. The country consists of 22 provinces, five autonomous regions, four municipalities, and two Special Administrative Regions (Hong Kong and Macau). The national capital is Beijing, and the most populous city and financial center is Shanghai. Modern Chinese trace their origins to a cradle of civilization in the fertile basin of the Yellow River in the North China Plain. The semi-legendary Xia dynasty in the 21st century BCE and the well-attested Shang and Zhou dynasties developed a bureaucratic political system to serve hereditary monarchies, or dyna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zeta Piscis Austrini
Zeta Piscis Austrini, Latinized from ζ Piscis Austrini, is an orange-hued star in the southern constellation of Piscis Austrinus. It has an apparent visual magnitude of +6.43, which is near the lower limit of stars that can be seen with the naked eye. Based upon an annual parallax shift of 7.55 mas as seen from the Gaia telescope, the star is located 413 ± 2 light years from the Sun. This is an evolved K-type giant star with a stellar classification of K1 III. It is a suspected variable star A variable star is a star whose brightness as seen from Earth (its apparent magnitude) changes with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are classified as .... References {{DEFAULTSORT:Zeta Piscis Austrini K-type giants Piscis Austrinus Piscis Austrini, Zeta Durchmusterung objects 213296 111138 8570 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta Piscis Austrini
Delta Piscis Austrini, Latinized from δ Piscis Austrini, is a yellow-hued star in the southern constellation of Piscis Austrinus. It is visible to the naked eye with an apparent visual magnitude of +4.175. There is a magnitude 9.86 common proper motion companion located at an angular separation of 5.2 arc seconds – the pair most likely form a binary star system. Based upon an annual parallax shift of 18.9796 mas as seen from the Gaia satellite, Delta Piscis Austrini is located 172 ± 2 light-years from the Sun. The primary, component A, is an evolved G-type giant star with a stellar classification of G8 III. At the age of about 3.74 billion years it is a red clump star, which indicates it is generating energy through helium fusion at its core. The star has an estimated 1.42 times the mass of the Sun and it radiates 52 times the solar luminosity from its photosphere at an effective temperature of 4.828 K. Delta Piscis Austrini is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arc Second
A minute of arc, arcminute (arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of one degree. Since one degree is of a turn (or complete rotation), one minute of arc 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 circumference is very near . A minute of arc is of a radian. A second of arc, arcsecond (arcsec), or arc second, denoted by the symbol , is of an arcminute, of a degree, of a turn, and (about ) of a radian. These units originated in Babylonian astronomy as sexagesimal 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 milliarcsecond (mas) and microarcsecond (μas), for instance, are commonly used in astron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angular Separation
Angular distance \theta (also known as angular separation, apparent distance, or apparent separation) is the angle between the two sightlines, or between two point objects as viewed from an observer. Angular distance appears in mathematics (in particular geometry and trigonometry) and all natural sciences (e.g. astronomy and geophysics). In the classical mechanics of rotating objects, it appears alongside angular velocity, angular acceleration, angular momentum, moment of inertia and torque. Use The term ''angular distance'' (or ''separation'') is technically synonymous with ''angle'' itself, but is meant to suggest the linear distance between objects (for instance, a couple of stars observed from Earth). Measurement Since the angular distance (or separation) is conceptually identical to an angle, it is measured in the same units, such as degrees or radians, using instruments such as goniometers or optical instruments specially designed to point in well-defined directions and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical Unit
The astronomical unit (symbol: au, or or AU) is a unit of length, roughly the distance from Earth to the Sun and approximately equal to or 8.3 light-minutes. The actual distance from Earth to the Sun varies by about 3% as Earth orbits the Sun, from a maximum (aphelion) to a minimum (perihelion) and back again once each year. The astronomical unit was originally conceived as the average of Earth's aphelion and perihelion; however, since 2012 it has been defined as exactly (see below for several conversions). 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. 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
