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Kappa Persei
Kappa Persei or κ Persei, is a triple star system in the northern constellation of Perseus. Based upon an annual parallax shift of 28.93 mas, it is located at a distance of 113 light-years from the Sun. The system consists of a spectroscopic binary, designated Kappa Persei A, which can be seen with the naked eye, having an apparent visual magnitude of 3.80. The third star, designated Kappa Persei B, is of magnitude 13.50. Kappa Persei A's two components are designated Kappa Persei Aa (officially named Misam , the traditional name of the entire system) and Ab. Nomenclature ''κ Persei'' ( Latinised to ''Kappa Persei'') is the system's Bayer designation. The designations of the two constituents as ''Kappa Persei A'' and ''B'', and those of ''A's'' components - ''Kappa Persei Aa'' and ''Ab'' - derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union ... [...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] |
Asterism (astronomy)
An asterism is an observed pattern or group of stars in the sky. Asterisms can be any identified pattern or group of stars, and therefore are a more general concept than the formally defined 88 constellations. Constellations are based on asterisms, but unlike asterisms, constellations outline and today completely divide the sky and all its celestial objects into regions around their central asterisms. For example, the asterism known as the Big Dipper comprises the seven brightest stars in the constellation Ursa Major. Another is the asterism of the Southern Cross, within the constellation of Crux. Asterisms range from simple shapes of just a few stars to more complex collections of many stars covering large portions of the sky. The stars themselves may be bright naked-eye objects or fainter, even telescopic, but they are generally all of a similar brightness to each other. The larger brighter asterisms are useful for people who are familiarizing themselves with the night sky. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleiades
The Pleiades (), also known as The Seven Sisters, Messier 45 and other names by different cultures, is an asterism and an open star cluster containing middle-aged, hot B-type stars in the north-west of the constellation Taurus. At a distance of about 444 light years, it is among the nearest star clusters to Earth. It is the nearest Messier object to Earth, and is the most obvious cluster to the naked eye in the night sky. It is also observed to house the reflection nebula NGC 1432, an HII Ionized region. The cluster is dominated by hot blue luminous stars that have formed within the last 100 million years. Reflection nebulae around the brightest stars were once thought to be left over material from their formation, but are now considered likely to be an unrelated dust cloud in the interstellar medium through which the stars are currently passing. This dust cloud is estimated to be moving at a speed of approximately 18 km/s relative to the stars in the cluster. Computer sim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyades (star Cluster)
The Hyades (; Greek Ὑάδες, also known as Caldwell 41, Collinder 50, or Melotte 25) is the nearest open cluster and one of the best-studied star clusters. Located about away from the Sun, it consists of a roughly spherical group of hundreds of stars sharing the same age, place of origin, chemical characteristics, and motion through space.Bouvier J, Kendall T, Meeus G, Testi L, Moraux E, Stauffer JR, James D, Cuillandre J-C, Irwin J, McCaughrean MJ, Baraffe I, Bertin E. (2008) Brown dwarfs and very low mass stars in the Hyades cluster: a dynamically evolved mass function. ''Astronomy & Astrophysics'', 481: 661-672. Abstract at http://adsabs.harvard.edu/abs/2008A%26A...481..661B. From the perspective of observers on Earth, the Hyades Cluster appears in the constellation Taurus, where its brightest stars form a "V" shape along with the still-brighter Aldebaran. However, Aldebaran is unrelated to the Hyades, as it is located much closer to Earth and merely happens to lie alon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proper Motion
Proper motion is the astrometric measure of the observed changes in the apparent places of stars or other celestial objects in the sky, as seen from the center of mass of the Solar System, compared to the abstract background of the more distant stars. The components for proper motion in the equatorial coordinate system (of a given epoch, often J2000.0) are given in the direction of right ascension (''μ''α) and of declination (''μ''δ). Their combined value is computed as the ''total proper motion'' (''μ''). It has dimensions of angle per time, typically arcseconds per year or milliarcseconds per year. Knowledge of the proper motion, distance, and radial velocity allows calculations of an object's motion from our star system's frame of reference and its motion from the galactic frame of reference – that is motion in respect to the Sun, and by coordinate transformation, that in respect to the Milky Way. Introduction Over the course of centuries, stars appear t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cosmic Dust
Cosmic dust, also called extraterrestrial dust, star dust or space dust, is dust which exists in outer space, or has fallen on Earth. Most cosmic dust particles measure between a few molecules and 0.1 mm (100 micrometers). Larger particles are called meteoroids. Cosmic dust can be further distinguished by its astronomical location: intergalactic dust, interstellar dust, interplanetary dust (such as in the zodiacal cloud) and circumplanetary dust (such as in a planetary ring). There are several methods to obtain space dust measurement. In the Solar System, interplanetary dust causes the zodiacal light. Solar System dust includes comet dust, asteroidal dust, dust from the Kuiper belt, and interstellar dust passing through the Solar System. Thousands of tons of cosmic dust are estimated to reach the Earth's surface every year, [...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 Kögler, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
12 Persei
12 Persei (12 Per) is a double-lined spectroscopic binary star system in the northern constellation Perseus. Its combined apparent magnitude is 4.94, which means it can be viewed with the naked eye. Based upon parallax measurements, this system is about 79 light years away from the Sun. The magnitude difference between the two components is estimated to be 0.51. Based upon this, the primary has a mass around 138% of the Sun, 155% of the Sun's radius, and shines with three times the Sun's luminosity. The smaller secondary component is also larger than the Sun, with 124% of the Sun's mass, 131% of the radius of the Sun, and has 186% of the Sun's luminosity. The stellar classification of the primary is F9 V, which suggests it is an F-type main sequence star. The pair have an estimated age of just over a billion years. The pair orbit each other with a period of 331 days and an eccentricity of 0.663. The semimajor axis In geometry, the major axis of an e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
16 Persei
16 Persei is a single, suspected variable star in the northern constellation of Perseus (constellation), Perseus, located approximately 121 light years away based on parallax. It is visible to the naked eye as a yellow-white hued star with an apparent visual magnitude of 4.22. This object is moving further from the Earth with a heliocentric radial velocity of +14 km/s. It displays a relatively high proper motion, traversing the celestial sphere at the rate of per year. Based upon a stellar classification of F2 III, this matches an aging giant star that has exhausted the hydrogen at its stellar core, core and is stellar evolution, evolving away from the main sequence. It is a possible pulsating Delta Scuti variable, although there is some uncertainty about this classification. However, Kunzli and North (1998) found no variation. The star is 1.44 billion years old with 1.8 times the mass of the Sun and 3.2 times the Sun's radius. It shows a high rotation rate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rho Persei
Rho Persei, Latinized from ρ Persei, is a star in the northern constellation of Perseus. It has the traditional name Gorgonea Tertia , being the third member of the quartet called the Gorgonea in reference to the Gorgons from the legend of Perseus. An apparent visual magnitude of +3.39 makes it visible to the naked eye, but a challenge to view from a well-lit urban environment. Based upon parallax measurements, it is located at a distance of roughly from Earth. Rho Persei is a semiregular variable star, whose apparent magnitude varies between 3.3 and 4.0 with periods of 50, 120 and 250 days. The star has reached the asymptotic giant branch of its evolution. It is a bright giant star with a stellar classification of M4 II. The outer envelope has an effective temperature of 3,479 K, giving it the red-orange hue of an M-type star. This star has a mass 1.9 times the mass of the Sun, while its radius has expanded to 143 times solar. It is radiating so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algol
ALGOL (; short for "Algorithmic Language") is a family of imperative computer programming languages originally developed in 1958. ALGOL heavily influenced many other languages and was the standard method for algorithm description used by the Association for Computing Machinery (ACM) in textbooks and academic sources for more than thirty years. In the sense that the syntax of most modern languages is "Algol-like", it was arguably more influential than three other high-level programming languages among which it was roughly contemporary: FORTRAN, Lisp, and COBOL. It was designed to avoid some of the perceived problems with FORTRAN and eventually gave rise to many other programming languages, including PL/I, Simula, BCPL, B, Pascal, and C. ALGOL introduced code blocks and the begin...end pairs for delimiting them. It was also the first language implementing nested function definitions with lexical scope. Moreover, it was the first programming language which gave detail ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
