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Gamma Cancri
Gamma Cancri, or γ Cancri, is a star in the northern constellation of Cancer. It is formally named Asellus Borealis , the traditional name of the system. Based on parallax measurements, it is located at a distance of approximately 181 light years from the Sun. The star is drifting further away with a radial velocity of 29 km/s. In 1910 this star was reported to be a spectroscopic binary by O. J. Lee, but is now considered a single star. Since it is near the ecliptic, it can be occulted by the Moon and, very rarely, by planets. Nomenclature ''γ Cancri'' ( Latinised to ''Gamma Cancri'') is the star's Bayer designation. It bore the traditional name ''Asellus Borealis'' (Latin for "northern donkey"). In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalogue and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems. It approved the name ... [...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] |
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the Roman Republic it became the dominant language in the Italian region and subsequently throughout the Roman Empire. Even after the fall of Western Rome, Latin remained the common language of international communication, science, scholarship and academia in Europe until well into the 18th century, when other regional vernaculars (including its own descendants, the Romance languages) supplanted it in common academic and political usage, and it eventually became a dead language in the modern linguistic definition. Latin is a highly inflected language, with three distinct genders (masculine, feminine, and neuter), six or seven noun cases (nominative, accusative, genitive, dative, ablative, and vocative), five declensions, four verb conjuga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hong Kong Space Museum
The Hong Kong Space Museum is an astronomy and space science museum located in Tsim Sha Tsui, Hong Kong. Opened on 8 October 1980, it is managed by the Leisure and Cultural Services Department of the Hong Kong Government. The building is notable for its hemispherical shape, which contains a planetarium, the only one in Hong Kong. The main facilities of the museum are located in a building next to the planetarium, showcasing information about the Solar System, cosmology, and spaceflight. Accessible from Salisbury Road, it is adjacent to the Hong Kong Cultural Centre, the Hong Kong Museum of Art, and the Tsim Sha Tsui Clock Tower. The Hong Kong Science Museum and the Hong Kong Museum of History are also located in Tsim Sha Tsui. History The idea of a planetarium was originally proposed in 1961 by the Urban Council. Ten years later, the Urban Services Department (USD) set up a working group to study overseas experience in establishing planetariums. The study was aimed at layi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eta Cancri
Eta Cancri, Latinized from η Cancri, is a single, orange-hued star in the zodiac constellation of Cancer. It is a faint star but visible to the naked eye with an apparent visual magnitude of 5.34. The annual parallax shift of 10.93 mas as seen from Earth yields a distance estimate of 155 light years from the Sun. It is moving further away with a radial velocity of +22 km/s. A stellar classification of K3 III for Eta Cancri indicates that, at the estimated age of 3.9 billion years old, it has left the main sequence and become an evolved giant star. The spectrum shows unusually strong absorption lines of cyanogen. It has 1.5 times the mass of the Sun and has expanded to 17 times the Sun's radius. The star is radiating 87 times the Sun's luminosity from its photosphere at an effective temperature of around 4,415 K. In Chinese astronomy, ''Ghost'' () refers to an asterism consisting of Theta Cancri, Eta Cancri, Gamma Cancri and Delta Cancri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theta Cancri
Theta Cancri, Latinised from θ Cancri, is a multiple star system in the zodiac constellation of Cancer. It is visible to the naked eye as a dim point of light with an apparent visual magnitude of +5.32. The system is located at a distance of approximately 450 light-years away from the Sun, based on parallax, and is drifting further away with a radial velocity of +44 km/s. Since it is near the ecliptic, it can be occulted by the Moon and, very rarely, by planets. The primary, designated component A, is K-type giant star with a stellar classification of K5 III, having exhausted the supply of hydrogen at its core, then cooled and expanded. At present it has 40 times the girth of the Sun. It is radiating 353 times the luminosity of the Sun at an effective temperature of . In Chinese astronomy, ''Ghost'' () refers to an asterism consisting of Theta Cancri, Eta Cancri, Gamma Cancri and Delta Cancri Delta Cancri (δ Cancri, abbreviated Delta Cnc, δ ... [...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] |
Ghost (Chinese Constellation)
The Ghost mansion () 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:Ghost (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] |
Courier Corporation
Dover Publications, also known as Dover Books, is an American book publisher founded in 1941 by Hayward and Blanche Cirker. It primarily reissues books that are out of print from their original publishers. These are often, but not always, books in the public domain. The original published editions may be scarce or historically significant. Dover republishes these books, making them available at a significantly reduced cost. Classic reprints Dover reprints classic works of literature, classical sheet music, and public-domain images from the 18th and 19th centuries. Dover also publishes an extensive collection of mathematical, scientific, and engineering texts. It often targets its reprints at a niche market, such as woodworking. Starting in 2015, the company branched out into graphic novel reprints, overseen by Dover acquisitions editor and former comics writer and editor Drew Ford. Most Dover reprints are photo facsimiles of the originals, retaining the original pagination and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Praesepe
The Beehive Cluster (also known as Praesepe (Latin for "manger" or "crib"), M44, NGC 2632, or Cr 189), is an open cluster in the constellation Cancer (constellation), Cancer. One of the nearest open clusters to Earth, it contains a larger population of stars than other nearby bright open clusters holding around 1,000 Star, stars. Under dark skies, the Beehive Cluster looks like a small Nebula, nebulous object to the naked eye, and has been known since ancient times. Classical astronomer Ptolemy described it as a "nebulous mass in the breast of Cancer". It was among the first objects that Galileo studied with his telescope. Age and proper motion coincide with those of the Hyades (star cluster), Hyades, suggesting they may share similar origins. Both clusters also contain red giants and white dwarfs, which represent later stages of stellar evolution, along with many main sequence stars. Distance to M44 is often cited to be between 160 and 187 parsecs (520–610 light years), b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta Cancri
Delta Cancri (δ Cancri, abbreviated Delta Cnc, δ Cnc) is a double star about 180 light-years from the Sun in the constellation of Cancer. Its two main constituents are designated Delta Cancri A and B. A is itself a binary star whose components are Delta Cancri Aa (formally named Asellus Australis , the traditional name of the entire system) and Ab. The star system is 0.08 degree north of the ecliptic, so it can be occulted by the Moon and more rarely by planets; it is occulted (eclipsed) by the sun from about 31 July to 2 August. Thus the star can be viewed the whole night, crossing the sky at the start of February. Nomenclature ''δ Cancri'' ( Latinised to ''Delta Cancri'') is the system's Bayer designation. The designations of the two constituents ''Delta Cancri A'' and ''B'', and those of ''A's'' components - ''Delta Cancri Aa'' and ''Ab'' - derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiple Star
A star system or stellar system is a small number of stars that orbit each other, bound by gravitational attraction. A large group of stars bound by gravitation is generally called a ''star cluster'' or ''galaxy'', although, broadly speaking, they are also star systems. Star systems are not to be confused with planetary systems, which include planets and similar bodies (such as comets). A star system of two stars is known as a ''binary star'', ''binary star system'' or ''physical double star''. If there are no tidal effects, no perturbation from other forces, and no transfer of mass from one star to the other, such a system is stable, and both stars will trace out an elliptical orbit around the barycenter of the system indefinitely. ''(See Two-body problem)''. Examples of binary systems are Sirius, Procyon and Cygnus X-1, the last of which probably consists of a star and a black hole. Multiple star systems A multiple star system consists of three or more stars that appear f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
