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Kappa Boötis
Kappa Boötis is a double star in the constellation Boötes. Its name is a Bayer designation that is Romanization of Greek, Latinized from κ Boötis, and abbreviated Kappa Boo or κ Boo. This star has the traditional name Asellus Tertius, which is pronouced and is Latin language, Latin for "third donkey colt". The components have an angular separation of 13.5 arcsec; viewable in a small telescope. Kappa Boötis is approximately from Earth. Properties κ1 Boötis is itself a double-lined spectroscopic binary star system. The primary component is an F-type main-sequence star star of class F2V, while the secondary is half the mass and much fainter. κ2 Boötis is classified as a Delta Scuti variable, Delta Scuti type variable star with a period of 1.08 hours Its brightness varies from magnitude +4.50 to +4.58. It is a slightly stellar evolution, evolved A8 subgiant, which indicates the hydrogen at its stellar core, core is all but exhausted. This star has more than doub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boötes (constellation)
Boötes ( ) is a constellation in the northern sky, located between 0° and +60° declination, and 13 and 16 hours of right ascension on the celestial sphere. The name comes from , which comes from 'herder, herdsman' or 'plowman' (literally, 'ox-driver'; from ''boûs'' 'cow'). One of the 48 constellations described by the 2nd-century astronomer Ptolemy, Boötes is now one of the 88 modern constellations. It contains the List of brightest stars, fourth-brightest star in the night sky, the orange giant Arcturus. Epsilon Boötis, or Izar, is a colourful multiple star popular with amateur astronomers. Boötes is home to many other bright stars, including eight above the fourth magnitude and an additional 21 above the fifth magnitude, making a total of 29 stars easily visible to the naked eye. History and mythology In ancient Babylon, the stars of Boötes were known as SHU.PA. They were apparently depicted as the god Enlil, who was the leader of the Babylonian religion, Babyloni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Projected Rotational Velocity
Stellar rotation is the angular motion of a star about its axis. The rate of rotation can be measured from the spectrum of the star, or by timing the movements of active features on the surface. The rotation of a star produces an equatorial bulge due to centrifugal force. As stars are not solid bodies, they can also undergo differential rotation. Thus the equator of the star can rotate at a different angular velocity than the higher latitudes. These differences in the rate of rotation within a star may have a significant role in the generation of a stellar magnetic field. In its turn, the magnetic field of a star interacts with the stellar wind. As the wind moves away from the star its angular speed decreases. The magnetic field of the star interacts with the wind, which applies a drag to the stellar rotation. As a result, angular momentum is transferred from the star to the wind, and over time this gradually slows the star's rate of rotation. Measurement Unless a sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Astrophysical Journal Supplement Series
''The Astrophysical Journal'' (''ApJ'') is a peer-reviewed scientific journal of astrophysics and astronomy, established in 1895 by American astronomers George Ellery Hale and James Edward Keeler. The journal discontinued its print edition and became an electronic-only journal in 2015. Since 1953, ''The Astrophysical Journal Supplement Series'' (''ApJS'') has been published in conjunction with ''The Astrophysical Journal'', with generally longer articles to supplement the material in the journal. It publishes six volumes per year, with two 280-page issues per volume. ''The Astrophysical Journal Letters'' (''ApJL''), established in 1967 by Subrahmanyan Chandrasekhar as Part 2 of ''The Astrophysical Journal'', is now a separate journal focusing on the rapid publication of high-impact astronomical research. The three journals were published by the University of Chicago Press for the American Astronomical Society until, in January 2009, publication was transferred to IOP Publi ... [...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 ecliptic is divided into four sectors that are associated with the Four Symbols, guardians in Chinese mythology, and further into 28 mansions. Stars around the north celestial pole are grouped into three enclosures (, ''yuán''). The system of 283 asterisms under the 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 S� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Purple Forbidden Enclosure
The Purple Forbidden enclosure ( Zǐ wēi yuán) is one of the San Yuan ( Sān yuán) or Three Enclosures. Stars and constellations of this group lie near the north celestial pole and are visible all year from temperate latitudes in the Northern Hemisphere. Asterisms The asterisms are: See also * Twenty-Eight Mansions The Twenty-Eight Mansions (), also called or , are part of the Chinese constellations system. They can be considered as the equivalent to the Zodiac, zodiacal constellations in Western astronomy, though the Twenty-eight Mansions reflect the move ... References Chinese constellations Chinese astrology Purple {{china-stub ... [...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] |
Lambda Boötis
Lambda Boötis is a star in the northern constellation of Boötes. Its name is a Bayer designation that is Latinized from λ Boötis, and abbreviated Lam Boo or λ Boo. It has the official name Xuange, pronounced . With an apparent visual magnitude of +4.18, it is faintly visible to the naked eye. Based on parallax measurements, it is distant from Earth. This star is drifting closer to the Sun with a radial velocity of −8 km/s. This is a white hued A-type main-sequence star with a stellar classification of A0p λB. It is the prototype of a group of rare stars known as Lambda Boötis stars, all of which are dwarf stars with unusually low abundances of metals in their spectra. Its diameter has been directly measured to be 1.7 times that of the Sun. This is a Delta Scuti variable star with a period of and an amplitude of 0.0020 in visual magnitude. This star displays an infrared excess that may be the result of a circumstellar disk of orbiting debris, or els ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iota Boötis
Iota Boötis is a wide binary star system in the constellation Boötes, approximately 96 light-years from Earth. Its name is a Bayer designation that is Romanization of Greek, Latinized from ι Boötis, and abbreviated Iota Boo or ι Boo. The brighter component has the traditional name Asellus Secundus, pronounced , which is Latin for "second donkey colt", and the Flamsteed designation 21 Boötis. It is faintly visible to the naked eye with a typical apparent visual magnitude of +4.75. Based on stellar parallax, parallax measurements, it is located at a distance of from the Earth. The star is drifting closer to the Sun with a radial velocity of −19 km/s. The companion is HD 234121, a K-type main-sequence star at an angular distance of 38.6 arcseconds; easily separated with binoculars. Components The primary component is a white hued A-type main-sequence star with a stellar classification of A7V. It is classified as a Delta Scuti variable, Delta Scuti-type varia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theta Boötis
Theta Boötis is a star in the northern constellation of Boötes the herdsman, forming a corner of the upraised left hand of this asterism. Its name is a Bayer designation that is Latinized from θ Boötis, and abbreviated Theta Boo or θ Boo. This star has the traditional name Asellus Primus, pronounced , which is Latin for "first donkey colt". Faintly visible to the naked eye, this star has a yellow-white hue with an apparent visual magnitude of 4.05. It is located at a distance of from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −10.6 km/s. It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.464 arc seconds per annum. Properties The stellar classification of Theta Boötis is F7 V, matching an F-type main-sequence star. It is a solar-type star that may be near the end of its main sequence lifetime based on a high luminosity for a star of its type. Theta Boötis is a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hipparcos
''Hipparcos'' was a scientific satellite of the European Space Agency (ESA), launched in 1989 and operated until 1993. It was the first space experiment devoted to precision astrometry, the accurate measurement of the positions and distances of celestial objects on the sky. This permitted the first high-precision measurements of the intrinsic brightnesses, proper motions, and parallaxes of stars, enabling better calculations of their distance and tangential velocity. When combined with radial velocity measurements from spectroscopy, astrophysicists were able to finally measure all six quantities needed to determine the motion of stars. The resulting ''Hipparcos Catalogue'', a high-precision catalogue of more than 118,200 stars, was published in 1997. The lower-precision ''Tycho Catalogue'' of more than a million stars was published at the same time, while the enhanced Tycho-2 Catalogue of 2.5 million stars was published in 2000. ''Hipparcos'' follow-up mission, '' Gaia'', was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flamsteed Designation
A Flamsteed designation is a combination of a number and constellation name that uniquely identifies most naked eye stars in the 88 modern constellations, modern constellations visible from southern England. They are named after John Flamsteed, author of the ''Historia Coelestis Britannica'', the first major star catalogue compiled with the aid of a telescope. Flamsteed’s own catalogue did not include what are now known as Flamsteed numbers, but its listing of stars in each constellation provided the basis for later astronomers to add them. Description Flamsteed designations for stars are similar to Bayer designations, except that they use numbers instead of Greek and Roman letters. Each star is assigned a number and the Latin genitive of the constellation it lies in (see 88 modern constellations for a list of constellations and the genitive forms of their names). Flamsteed designations were assigned to 2554 stars. The numbers were originally assigned in order of increasing righ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bright Star Catalogue
The Bright Star Catalogue, also known as the Yale Catalogue of Bright Stars, Yale Bright Star Catalogue, or just YBS, is a star catalogue that lists all stars of stellar magnitude 6.5 or brighter, which is roughly every star visible to the naked eye from Earth. The catalog lists 9,110 objects, of which 9,095 are stars, 11 are novae or supernovae (which were "bright stars" only at the time when they were at their peak), and four are non-stellar objects which are the globular clusters 47 Tucanae (designated HR 95) and NGC 2808 (HR 3671), and the open clusters NGC 2281 (HR 2496) and Messier 67 (HR 3515). The catalogue is fixed in number of entries, but its data is maintained, and it is appended with a comments section about the objects that has been steadily enhanced. The abbreviation for the catalog as a whole is BS or YBS but all citations of stars it indexes use HR before the catalog number, a homage to the catalog's direct predecessor, published ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
