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ζ Centauri
Zeta Centauri, Latinized from ζ Centauri, also named Leepwal, is a binary star system in the southern constellation of Centaurus. With a combined apparent visual magnitude of +2.55, it is one of the brighter members of the constellation. This system is close enough to the Earth that its distance can be measured directly using the parallax technique. This yields a value of roughly , with a 1.6% margin of error. It is drifting further away with a radial velocity of +6.5 km/s. ζ Cen is a double-lined spectroscopic binary system, which indicates that the orbital motion was detected by shifts in the absorption lines of their combined spectra caused by the Doppler effect. The two stars orbit each other over a period of slightly more than eight days with an orbital eccentricity of about 0.5. The estimated angular separation of the pair is 1.4 mas. At an estimated age of 40 million years, the primary component of this system appears to be in the subgiant stage of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centaurus
Centaurus () is a bright constellation in the southern sky. One of the 88 modern constellations by area, largest constellations, Centaurus was included among the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one of the IAU designated constellations, 88 modern constellations. In Greek mythology, Centaurus represents a centaur; a creature that is half human, half horse (another constellation named after a centaur is one from the zodiac: Sagittarius (constellation), Sagittarius). Notable stars include Alpha Centauri, the nearest star system to the Solar System, its neighbour in the sky Beta Centauri, and V766 Centauri, HR 5171, one of the largest stars yet discovered. The constellation also contains Omega Centauri, the brightest globular cluster as visible from Earth and the largest identified in the Milky Way, possibly a remnant of a dwarf galaxy. Notable features Stars Centaurus contains several very bright stars. Its alpha and beta stars are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subgiant Star
A subgiant is a star that is brighter than a normal main-sequence star of the same spectral class, but not as bright as giant stars. The term subgiant is applied both to a particular spectral luminosity class and to a stage in the evolution of a star. Yerkes luminosity class IV The term subgiant was first used in 1930 for class G and early K stars with absolute magnitudes between +2.5 and +4. These were noted as being part of a continuum of stars between obvious main-sequence stars such as the Sun and obvious giant stars such as Aldebaran, although less numerous than either the main sequence or the giant stars. The Yerkes spectral classification system is a two-dimensional scheme that uses a letter and number combination to denote the temperature of a star (e.g. A5 or M1) and a Roman numeral to indicate the luminosity relative to other stars of the same temperature. Luminosity class IV stars are the subgiants, located between main-sequence stars (luminosity class V) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xi¹ Centauri
Xi1 Centauri, Latinized from ξ1 Centauri, is a solitary star in the southern constellation of Centaurus. It is visible to the naked eye with an apparent visual magnitude of +4.83. With an annual parallax shift of 14.79 mas, it is located around 221 light years from the Sun. At that distance, the apparent visual magnitude of the star is diminished by an interstellar extinction factor of 0.10 due to intervening dust. Just 17 arc minutes to the east of Xi1 Centauri lies the galaxy NGC 4945. This is an A-type main sequence star with a stellar classification of A0 V. It is about 125 million years old with a relatively high rate of spin, having a projected rotational velocity of 185 km/s. The star has an estimated 2.4 times the mass of the Sun and about 2.7 times the Sun's radius. It is radiating 43 times the solar luminosity from its outer atmosphere at an effective temperature The effective temperature of a body such as a star or planet is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 117440
HD 117440, also known by its Bayer designation d Centauri, is a binary star system in the southern constellation of Centaurus. It is visible to the naked eye with a combined apparent visual magnitude of 3.90. The distance to this system is approximately 900 light years based on parallax measurements. It is drifting closer to the Sun with a radial velocity of −2 km/s. A companion star was first reported by T. J. J. See in 1897 at an angular separation of from the primary. Orbital elements for the pair were published by W. S. Finsen in 1962 then updated in 1964, yielding an orbital period of 83.1 years with a semimajor axis of and an eccentricity of 0.52. Both components are evolved G-type giant star A giant star has a substantially larger radius and luminosity than a main-sequence (or ''dwarf'') star of the same surface temperature. They lie above the main sequence (luminosity class V in the Yerkes spectral classification) on the Hertzsp ...s w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2 Centauri
2 Centauri is a single star in the southern constellation of Centaurus, located approximately 183 light-years from Earth. It has the Bayer designation g Centauri; ''2 Centauri'' is the Flamsteed designation. This object is visible to the naked eye as faint, red-hued star with an apparent visual magnitude of 4.19. It is moving away from the Earth with a heliocentric radial velocity of +41 km/s. The star is a member of the HR 1614 supercluster. This is an evolved red giant star with a stellar classification of M5 III. In 1951, Alan William James Cousins announced that the star, then called g Centauri, is a variable star. It was given its variable star designation, V806 Centauri, in 1978. It is classified as a semiregular variable star and its brightness varies from magnitude +4.16 to +4.26 with a period of 12.57 days. The star has around 70 times the Sun's radius and is radiating 72 times the Sun's luminosity from its enlarged photosphere at an effective temper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theta Centauri
Theta Centauri or θ Centauri, officially named Menkent (), is a single star in the southern constellation of Centaurus, the centaur. With an apparent visual magnitude of +2.06, it is the fourth-brightest member of the constellation. Based on parallax measurements obtained during the Hipparcos mission, it is about distant. It has a relatively high proper motion, traversing the celestial sphere at the rate of . This suggests that Menkent may have originated in the outer disk of the Milky Way and is merely passing through the solar neighborhood. Nomenclature ''θ Centauri'', Latinised to ''Theta Centauri'', is the star's Bayer designation. It bore the traditional name of ''Menkent'' derived from the Arabic word مَنْكِب (mankib) for "shoulder" (of the Centaur), apparently blended with a shortened form of "kentaurus" (centaur). In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalog and standardize proper names fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eta Centauri
Eta Centauri, Romanization of Greek, Latinized from η Centauri, is a star in the southern constellation of Centaurus. It has an apparent visual magnitude of +2.35 and is located at a distance of around . The stellar classification of this star is B1.5 Vne, indicating that it is a B-type main sequence star. The 'n' suffix means that the absorption lines are broadened from rapid rotation and the 'e' that it shows emission lines in its spectrum. It has a projected rotational velocity of 330 km s−1 and completes a full rotation in less than a day. As a Be star, it has variable emissions in its hydrogen spectral lines. This emission can be modelled by a decretion disk of gas that has been ejected from the star by its rapid rotation and now follows a near-Keplerian orbit around the central body. Its brightness is also slightly variable, and it is classified as a Gamma Cassiopeiae variable star with multiple periods of variability. The International Variable Star In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horn (Chinese Constellation)
The Horn mansion (角宿, pinyin: Jiǎo Xiù) is one of the Twenty-eight mansions of the Chinese constellations. It is one of the eastern mansions of the Azure Dragon The Azure Dragon ( zh, c=青龍, p=Qīnglóng) is one of the Dragon King, Dragon Gods who represent the mount or Chthonic deities, chthonic forces of the Wufang Shangdi, Five Regions' Highest Deities (). It is also one of the Four Symbols o .... Asterisms References {{DEFAULTSORT:Horn (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] |
Alpha Gruis
Alpha Gruis is the brightest star in the southern constellation of Grus (constellation), Grus. It is officially named Alnair; ''Alpha Gruis'' is the star's Bayer designation, which is Latinisation of names, Latinized from α Gruis and abbreviated α Gru. With an apparent visual magnitude, magnitude of 1.74, it is List of brightest stars, one of the brightest stars in the sky and one of List of stars for navigation, the fifty-eight stars selected for celestial navigation. Alpha Gruis is a single, B-type main-sequence star located at a distance of . Nomenclature ''α Gruis'' (Latinisation of names, Latinised to ''Alpha Gruis'') is the star's Bayer designation. (Its first depiction in a Celestial cartography, celestial atlas was in Johann Bayer's ''Uranometria'' of 1603.) It bore the traditional name ''Alnair'' or ''Al Nair'' (sometimes ''Al Na'ir'' in List_of_selected_stars_for_navigation, lists of stars used by navigators), from the Arabic ''al-nayyir'' "the bright one", ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Southern Cross
CRUX is a lightweight x86-64 Linux distribution targeted at experienced Linux users and delivered by a tar.gz-based package system with BSD-style initscripts. It is not based on any other Linux distribution. It also utilizes a ports system to install and upgrade applications. Although ''crux'' is the Latin word for "cross," the choice of the name "CRUX" itself has no meaning. Per Lidén chose it because it "sounded cool," and ends in "X" which puts it in line with various other Unix flavors such as IRIX, Ultrix, Mac OS X and IBM AIX. Installation CRUX does not include a GUI installation program. Instead, the user boots the kernel stored on either a CD or diskette; partitions the hard disk drive(s) to which the operating system will be installed (using a program such as fdisk or cfdisk); creates the appropriate file systems on the various partitions; mounts the CD or NFS share along with the partitions made previously for use by the package installation script; comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Star Names
''Star Names: Their Lore and Meaning'' is an 1899 book by Richard Hinckley Allen, that discusses the names of stars, constellations, and their histories. Background and authorship Richard Hinckley Allen (1838, near Buffalo, New York – 1908, Northampton, Massachusetts) was a youthful polymath with interests in "nature, astronomy, ornithology, and literature" whom his classmates described as "the walking encyclopedia"; after a college year spent at Yale, a pursuit abandoned because of problems with his eyesight, he traveled and then "joined his father’s export trade business". Allen's interest in astronomy, and in star names in particular, may have been stimulated by his coming across such a name with which he was unfamiliar, after which " spent many years researching astronomical nomenclature... primarily for personal enjoyment". With the encouragement of professors from Yale and Princeton, and from personal friends, Allen proceeded to publish the information he had gathere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
