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Libra (constellation)
Libra is a constellation of the zodiac and is located in the Southern celestial hemisphere. Its name is Latin for weighing scales. Its old astronomical symbol is (♎︎). It is fairly faint, with no apparent magnitude, first magnitude stars, and lies between Virgo (constellation), Virgo to the west and Scorpius to the east. Beta Librae, also known as Zubeneschamali, is the brightest star in the constellation. Three star systems are known to have planets. Features Stars Overall, there are 83 stars within the constellation's borders brighter than or equal to apparent magnitude 6.5. The brightest stars in Libra form a quadrilateral, quadrangle that distinguishes it for the unaided observer. Traditionally, Alpha and Beta Librae are considered to represent the scales' balance beam, while Gamma and Sigma are the weighing pans. Alpha Librae, called Zubenelgenubi, is a multiple star system divisible into two stars when seen through binoculars, The primary (Alpha2 Librae) is a blue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weighing Scale
A scale or balance is a device used to measure weight or mass. These are also known as mass scales, weight scales, mass balances, massometers, and weight balances. The traditional scale consists of two plates or bowls suspended at equal distances from a fulcrum. One plate holds an object of unknown mass (or weight), while objects of known mass or weight, called '' weights'', are added to the other plate until mechanical equilibrium is achieved and the plates level off, which happens when the masses on the two plates are equal. The perfect scale rests at neutral. A spring scale will make use of a spring of known stiffness to determine mass (or weight). Suspending a certain mass will extend the spring by a certain amount depending on the spring's stiffness (or spring constant). The heavier the object, the more the spring stretches, as described in Hooke's law. Other types of scales making use of different physical principles also exist. Some scales can be calibrate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weighing Scales
A scale or balance is a device used to measure weight or mass. These are also known as mass scales, weight scales, mass balances, massometers, and weight balances. The traditional scale consists of two plates or bowls suspended at equal distances from a fulcrum. One plate holds an object of unknown mass (or weight), while objects of known mass or weight, called '' weights'', are added to the other plate until mechanical equilibrium is achieved and the plates level off, which happens when the masses on the two plates are equal. The perfect scale rests at neutral. A spring scale will make use of a spring of known stiffness to determine mass (or weight). Suspending a certain mass will extend the spring by a certain amount depending on the spring's stiffness (or spring constant). The heavier the object, the more the spring stretches, as described in Hooke's law. Other types of scales making use of different physical principles also exist. Some scales can be calibrated to read i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta Librae
Delta Librae, Latinized from δ Librae, is a variable star in the constellation Libra. It has the traditional name Zuben Elakribi, a variant of the traditional name of Gamma Librae. With μ Virginis it forms one of the Akkadian lunar mansions ''Mulu-izi''(meaning "Man-of-fire"). δ Librae is approximately 350 light years from the Earth and the primary, component A, belongs to the spectral class B9.5V, indicating it is a B-type main-sequence star. It is visible to the naked eye with an apparent visual magnitude of 4.93 and is moving closer to the Sun with a radial velocity of −39 km/s. This is an Algol-like eclipsing binary star system, with a period of 2.3274 days and an eccentricity of 0.07. Its apparent magnitude varies from 4.91 to 5.90. The secondary is filling its Roche lobe and there is evidence of large-scale mass transfer in the past, with the secondary being more evolved than the primary despite now being less massive. Along with λ Tauri, it was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mu Librae
μ Librae (Latinised as Mu Librae) is the Bayer designation for a probable triple star system in the zodiac constellation of Libra. They have a combined apparent visual magnitude of 5.32, which is bright enough to be faintly visible to the naked eye. With an annual parallax shift of 13.71 mas, the system is located at an estimated distance of around 240 light years. The inner pair consists of two A-type stars that, as of 2006, had an angular separation of 1.79 arc seconds along a position angle of 5.5°. They have an estimated physical separation of 139 AU. The primary, component A, is a visual magnitude 5.69 magnetic Ap star showing overabundances of the elements aluminum, strontium, chromium, and europium. Hence, it has a stellar classification of A1pSrEuCr. It is a photometric variable with periods of and . The surface magnetic field strength is 1,375 Gauss. The secondary, component B, is an Am star with a stellar classification In astron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
25 Librae
5 (five) is a number, numeral and digit. It is the natural number, and cardinal number, following 4 and preceding 6, and is a prime number. Humans, and many other animals, have 5 digits on their limbs. Mathematics 5 is a Fermat prime, a Mersenne prime exponent, as well as a Fibonacci number. 5 is the first congruent number, as well as the length of the hypotenuse of the smallest integer-sided right triangle, making part of the smallest Pythagorean triple ( 3, 4, 5). 5 is the first safe prime and the first good prime. 11 forms the first pair of sexy primes with 5. 5 is the second Fermat prime, of a total of five known Fermat primes. 5 is also the first of three known Wilson primes (5, 13, 563). Geometry A shape with five sides is called a pentagon. The pentagon is the first regular polygon that does not tile the plane with copies of itself. It is the largest face any of the five regular three-dimensional regular Platonic solid can have. A conic is determine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iota Librae
The Bayer designation Iota Librae (ι Lib / ι Librae) is shared by two star systems, in the constellation Libra: * ι¹ Librae (24 Librae), also known simply as ι Librae (iota Librae) * ι² Librae (25 Librae) The pair have an angular separation of just . They can be viewed as a double star In observational astronomy, a double star or visual double is a pair of stars that appear close to each other as viewed from Earth, especially with the aid of optical telescopes. This occurs because the pair either forms a binary star (i.e. a ... with a pair of binoculars or a small telescope. References {{SIA , astronomical objects Librae, Iota Libra (constellation) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orange Giant
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 Hertzsprung–Russell diagram and correspond to luminosity classes II and III. The terms ''giant'' and ''dwarf'' were coined for stars of quite different luminosity despite similar temperature or spectral type (namely K and M) by Ejnar Hertzsprung in 1905 or 1906. Giant stars have radii up to a few hundred times the Sun and luminosities over 10 times that of the Sun. Stars still more luminous than giants are referred to as supergiants and hypergiants. A hot, luminous main-sequence star may also be referred to as a giant, but any main-sequence star is properly called a dwarf, regardless of how large and luminous it is. Formation A star becomes a giant after all the hydrogen available for fusion at its core has been depleted and, as a result ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamma Librae
Gamma Librae (γ Librae, abbreviated Gamma Lib, γ Lib) is a suspected binary star system in the constellation of Libra. It is visible to the naked eye, having an apparent visual magnitude of +3.91. Based upon an annual parallax shift of 19.99 mas as seen from Earth, it lies at a distance of 163 light years. The primary component (designated Gamma Librae A) has been formally named Zubenelhakrabi , the traditional name of the system. Nomenclature ''γ Librae'' ( Latinised to ''Gamma Librae'') is the system's Bayer designation. The designations of the two components as ''Gamma Librae A'' and ''B'' derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU). Gamma Librae bore the traditional name ''Zuben (el) Hakrabi'' (also rendered as ''Zuben-el-Akrab'' and corrupted as ''Zuben Hakraki''). The name is a modification of the Arabic زبانى العقرب ''Z ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha Librae
Alpha Librae (α Librae, abbreviated Alpha Lib, α Lib) is a double star and, despite its 'alpha' designation, it is the second-brightest star system (or star) in the constellation of Libra. The two components are designated α1 Librae and α2 Librae. The system bore the traditional name of Zubenelgenubi , though the International Astronomical Union now regards that name as only applying to α2 Librae. Alpha2 Librae is 0.33 degrees north of the ecliptic so it can be occulted by the Moon and (very rarely) by planets. It was occulted by Venus on October 25, 1947; the next occultation by a planet will be by Mercury on 10 November 2052.Peuschel, Marco (2003)"Astronomische Ereignisse der besonderen Art". Retrieved July 10, 2005. Both components are eclipsed (occulted) by the sun from about 7–9 November. Thus the star can be viewed the whole night, crossing the sky, in early May. Nomenclature ''α Librae'' ( Latinised to ''Alpha Librae'') is the system's Bayer designation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadrilateral
In Euclidean geometry, geometry a quadrilateral is a four-sided polygon, having four Edge (geometry), edges (sides) and four Vertex (geometry), corners (vertices). The word is derived from the Latin words ''quadri'', a variant of four, and ''latus'', meaning "side". It is also called a tetragon, derived from Greek "tetra" meaning "four" and "gon" meaning "corner" or "angle", in analogy to other polygons (e.g. pentagon). Since "gon" means "angle", it is analogously called a quadrangle, or 4-angle. A quadrilateral with vertices A, B, C and D is sometimes denoted as \square ABCD. Quadrilaterals are either simple polygon, simple (not self-intersecting), or complex polygon, complex (self-intersecting, or crossed). Simple quadrilaterals are either convex polygon, convex or concave polygon, concave. The Internal and external angle, interior angles of a simple (and Plane (geometry), planar) quadrilateral ''ABCD'' add up to 360 Degree (angle), degrees, that is :\angle A+\angle B+\angle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sky & Telescope
''Sky & Telescope'' (''S&T'') is a monthly magazine covering all aspects of amateur and professional astronomy, including what to see in the sky tonight and new findings in astronomy. Other topics covered include: *observing guides for planets, galaxies, star clusters, and other objects visible in the night sky *reviews of telescopes and other astronomical equipment, books, and software *events in the amateur astronomy community * amateur telescope making * astrophotography The articles are intended for the informed lay reader and include detailed discussions of current discoveries, frequently by participating scientists. The magazine is illustrated in full color, with both amateur and professional photography of celestial sights, as well as tables and charts of upcoming celestial events. History ''Sky & Telescope'' was founded by Charles A. Federer and his wife Helen Spence Federer. The duo had formed the Sky Publishing Corporation in late 1939 to manage a magazine called '' T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
