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β UMi
Kochab , Bayer designation Beta Ursae Minoris (β Ursae Minoris, abbreviated β UMi, Beta UMi), is the brightest star in the bowl of the Little Dipper asterism (which is part of the constellation of Ursa Minor), and only slightly fainter than Polaris, the northern pole star and brightest star in Ursa Minor. Kochab is 16 degrees from Polaris and has an apparent visual magnitude of 2.08. The distance to this star from the Sun can be deduced from the parallax measurements made during the Hipparcos mission, yielding a value of . Amateur astronomers can use Kochab as a precise guide for equatorial mount alignment: The celestial north pole is located 38 arcminutes away from Polaris, very close to the line connecting Polaris with Kochab. Nomenclature ''β Ursae Minoris'' ( Latinised to ''Beta Ursae Minoris'') is the star's Bayer designation. It bore the traditional name ''Kochab'', which appeared in the Renaissance and has an uncertain meaning. It may be from or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ursa Minor
Ursa Minor (, contrasting with Ursa Major), also known as the Little Bear, is a constellation located in the far northern celestial hemisphere, northern sky. As with the Great Bear, the tail of the Little Bear may also be seen as the handle of a Ladle (spoon), ladle, hence the North American name, Little Dipper: seven stars with four in its bowl like its partner the Big Dipper. Ursa Minor was one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and remains one of the 88 modern constellations. Ursa Minor has traditionally been important for navigation, particularly by Sailor, mariners, because of Polaris being the north pole star. Polaris, the brightest star in the constellation, is a yellow-white supergiant and the brightest Cepheid variable star in the night sky, ranging in apparent magnitude from 1.97 to 2.00. Beta Ursae Minoris, also known as Kochab, is an aging star that has swollen and cooled to become an orange giant with an apparent magnitude of 2.08 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mercury (planet)
Mercury is the first planet from the Sun. It is a rocky planet with a trace atmosphere. While it is the List of Solar System objects by size, smallest and least massive planet of the Solar System, its surface gravity is slightly higher than that of Mars. The surface of Mercury is similar to Earth's Moon, heavily Impact crater, cratered, with expansive rupes system, generated from thrust faults, and bright ray systems, formed by ejecta. Its largest crater, Caloris Planitia, has a diameter of , which is about one-third the diameter of the planet (). Being the most inferior planet, inferior orbiting planet it appears in Earth's sky, always close to the Sun, either as a "morning star" or an "evening star". It stays most of the time the closest to all other planets and is the planet with the highest delta-v needed to travel to from all other planets of the Solar System. Mercury's sidereal year (88.0 Earth days) and sidereal day (58.65 Earth days) are in a 3:2 ratio. This relation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellar Evolution
Stellar evolution is the process by which a star changes over the course of time. Depending on the mass of the star, its lifetime can range from a few million years for the most massive to trillions of years for the least massive, which is considerably longer than the current age of the universe. The table shows the lifetimes of stars as a function of their masses. All stars are formed from Gravitational collapse, collapsing clouds of gas and dust, often called nebulae or molecular clouds. Over the course of millions of years, these protostars settle down into a state of equilibrium, becoming what is known as a main sequence star. Nuclear fusion powers a star for most of its existence. Initially the energy is generated by the fusion of hydrogen atoms at the stellar core, core of the main-sequence star. Later, as the preponderance of atoms at the core becomes helium, stars like the Sun begin to fuse hydrogen along a spherical shell surrounding the core. This process causes the st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellar Classification
In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction grating into a spectrum exhibiting the Continuum (spectrum), rainbow of colors interspersed with spectral lines. Each line indicates a particular chemical element or molecule, with the line strength indicating the abundance of that element. The strengths of the different spectral lines vary mainly due to the temperature of the photosphere, although in some cases there are true abundance differences. The ''spectral class'' of a star is a short code primarily summarizing the ionization state, giving an objective measure of the photosphere's temperature. Most stars are currently classified under the Morgan–Keenan (MK) system using the letters ''O'', ''B'', ''A'', ''F'', ''G'', ''K'', and ''M'', a sequence from the hottest (''O'' type) to the cool ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Giant
A red giant is a luminous giant star of low or intermediate mass (roughly 0.3–8 solar masses ()) in a late phase of stellar evolution. The stellar atmosphere, outer atmosphere is inflated and tenuous, making the radius large and the surface temperature around or lower. The appearance of the red giant is from yellow-white to reddish-orange, including the stellar classification, spectral types K and M, sometimes G, but also S-type star, class S stars and most carbon stars. Red giants vary in the way by which they generate energy: * most common red giants are stars on the red-giant branch (RGB) that are still stellar nucleosynthesis, fusing hydrogen into helium in a shell surrounding an inert helium core * red-clump stars in the cool half of the horizontal branch, fusing helium into carbon in their cores via the triple-alpha process * asymptotic-giant-branch (AGB) stars with a helium burning shell outside a degenerate carbon–oxygen core, and a hydrogen-burning shell just beyo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chinese Star Name
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 Sì'', t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Σ 1694
Struve 1694 (Σ 1694, Struve 1694) is a double star in the constellation Camelopardalis. Σ 1694 is a double star, with components of magnitudes 5.3m and 5.9m: *Σ 1694A ( HD 112028) is a white A-type giant star with an apparent magnitude of 5.28m. It is approximately 300 light years from Earth. *Σ 1694B ( HD 112014) is a spectroscopic binary consisting of two A-type main sequence stars. Norton's Star Atlas describes the pair as yellowish and bluish. Σ 1694 was also known as 32 H. Camelopardalis, Hevelius' 32nd of Camelopardalis. It is not Flamsteed's "32 Camelopardalis", which is ξ Aurigae. In the ''British Association Catalogue'', the star pair are listed as being in Ursa Minor. Chinese name In Chinese, (), meaning ''North Pole'', refers to an asterism consisting of Σ 1694, γ Ursae Minoris, β Ursae Minoris, 5 Ursae Minoris and 4 Ursae Minoris. Consequently, Σ 1694 itself is known as (, .), representing (), meaning ''Celestial Pivot''. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
4 Ursae Minoris
4 Ursae Minoris is a binary star system in the northern circumpolar constellation Ursa Minor. It is faintly visible to the naked eye with an apparent visual magnitude of 4.80. Based upon an annual parallax shift of as seen from Earth's orbit, it is located roughly 460 light years from the Sun. It is moving further away with a heliocentric radial velocity of +5.9 km/s. This is a single-lined spectroscopic binary star system with an orbital period of 1.66 years and an eccentricity of 0.14. The primary is a red giant of spectral type K3-IIIb Fe-0.5, a star that has used up its core hydrogen and is expanding. The suffix notation indicates the spectrum displays a mild underabundance of iron for a star of its type. It has expanded to around 28 times the Sun's radius and is radiating 437 times the Sun's luminosity from its enlarged photosphere at an effective temperature The effective temperature of a body such as a star or planet is the temperature of a b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5 Ursae Minoris
5 Ursae Minoris is a star in the circumpolar constellation of Ursa Minor. It is a faint star but visible to the naked eye with an apparent visual magnitude of 4.253. The distance to this star, as determined from an annual parallax shift of , is about 110 pc. It is moving further away with a heliocentric radial velocity of +9 km/s. With an age of around two billion years, this is an evolved red giant with a stellar classification of K4-III; a star that has used up its core hydrogen and has expanded. It is a mild barium star, which may indicate it is a binary with a white dwarf companion, and is very lithium-weak. The star has an estimated 1.86 times the mass of the Sun and has expanded to about 16 times the Sun's radius. It is radiating 447 times the Sun's luminosity from its enlarged photosphere at an effective temperature The effective temperature of a body such as a star or planet is the temperature of a black body that would emit the same total amount of el ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamma Ursae Minoris
Gamma Ursae Minoris (γ Ursae Minoris, abbreviated Gamma UMi, γ UMi), also named Pherkad , is a star in the northern constellation of Ursa Minor. Together with Beta Ursae Minoris (Kochab), it forms the end of the dipper pan of the "Little Dipper", which is an asterism forming the tail of the bear. Based upon parallax measurements obtained during the Hipparcos mission, it is approximately from the Sun. Nomenclature ''γ Ursae Minoris'' ( Latinised to ''Gamma Ursae Minoris'') is the star's Bayer designation. The fainter 11 Ursae Minoris has been called ''γ1 Ursae Minoris'', in which case ''Gamma Ursae Minoris'' would be designated ''γ2''. However this usage is rarely seen. Gamma Ursae Minoris bore the traditional name ''Pherkad'', which derived from the Arabic فرقد ''farqad'' "calf", short for ''aḫfa al farkadayn'' "the dim one of the two calves", that is Pherkad and Kochab (the full name Ahfa al Farkadain is traditionally applied to Zeta Ursae Minoris). Gamm ... [...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] |
