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Kappa Coronae Australis
The Bayer designation κ Coronae Australis (Kappa Coronae Australis) is shared by two stars in the constellation Corona Australis: * Kappa1 Coronae Australis, HR 6952 * Kappa2 Coronae Australis, HR 6953 It was found to be a double star by English astronomer John Herschel in 1836. The pair have an angular separation Angular distance \theta (also known as angular separation, apparent distance, or apparent separation) is the angle between the two sightlines, or between two point objects as viewed from an observer. Angular distance appears in mathematics (in pa ... of along a position angle of 359°. References {{Set index article , astronomical objects Corona Australis Coronae Australis, Kappa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bayer Designation
A Bayer designation is a stellar designation in which a specific star is identified by a Greek or Latin letter followed by the genitive form of its parent constellation's Latin name. The original list of Bayer designations contained 1,564 stars. The brighter stars were assigned their first systematic names by the German astronomer Johann Bayer in 1603, in his star atlas ''Uranometria''. Bayer catalogued only a few stars too far south to be seen from Germany, but later astronomers (including Nicolas-Louis de Lacaille and Benjamin Apthorp Gould) supplemented Bayer's catalog with entries for southern constellations. Scheme Bayer assigned a lowercase Greek letter (alpha (α), beta (β), gamma (γ), etc.) or a Latin letter (A, b, c, etc.) to each star he catalogued, combined with the Latin name of the star's parent constellation in genitive (possessive) form. The constellation name is frequently abbreviated to a standard three-letter form. For example, Aldebaran in the constellation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constellation
A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the earliest constellations likely go back to prehistory. People used them to relate stories of their beliefs, experiences, creation myth, creation, or mythology. Different cultures and countries adopted their own constellations, some of which lasted into the early 20th century before today's constellations were internationally recognized. The recognition of constellations has changed significantly over time. Many changed in size or shape. Some became popular, only to drop into obscurity. Some were limited to a single culture or nation. The 48 traditional Western constellations are Greek. They are given in Aratus' work ''Phenomena'' and Ptolemy's ''Almagest'', though their origin probably predates these works by several centuries. Constellation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corona Australis (constellation)
Corona Australis is a constellation in the Southern Celestial Hemisphere. Its Latin name means "southern crown", and it is the southern counterpart of Corona Borealis, the northern crown. It is one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations. The Ancient Greeks saw Corona Australis as a wreath rather than a crown and associated it with Sagittarius or Centaurus. Other cultures have likened the pattern to a turtle, ostrich nest, a tent, or even a hut belonging to a rock hyrax. Although fainter than its northern counterpart, the oval- or horseshoe-shaped pattern of its brighter stars renders it distinctive. Alpha and Beta Coronae Australis are the two brightest stars with an apparent magnitude of around 4.1. Epsilon Coronae Australis is the brightest example of a W Ursae Majoris variable in the southern sky. Lying alongside the Milky Way, Corona Australis contains one of the closest star-forming region ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kappa1 Coronae Australis
Kappa1 Coronae Australis (Kappa1 CrA), Latinized from κ1 Coronae Australis, is a star located in the southern constellation Corona Australis. It has an apparent magnitude of 6.17, placing it near the limit for naked eye visibility. There has been some disagreement about the object's distance. The ''New Hipparcos Reduction'' calculate a parallax of , yielding a distance of . This estimate is poorly constrained. New analysis from the Gaia spacecraft find that it has a physical relation to κ2 Coronae Australis. Both of their currently parallaxes place them around 700 light years away. As of 2018, both stars have an angular separation of along a position angle of . Kappa1 CrA has a stellar classification of A0 IV, indicating that it is a slightly evolved A-type star. At present it has 2.8 times the mass of the Sun and a slightly enlarged radius of . It radiates at 179 times the luminosity of the Sun from its photosphere at an effective temperature of . Kappa1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kappa2 Coronae Australis
Kappa2 Coronae Australis (Kappa2 CrA), Latinized from κ2 Coronae Australis, is the primary of a probable binary system located in the southern constellation Corona Australis. It is visible to the naked eye as a bluish-white hued star with an apparent visual magnitude of 5.59. The distance to this star is roughly 710 light years based on Gaia DR3 parallax measurements. The radial velocity is poorly constrained, but the star appears to be moving closer with a radial velocity of around . At its current distance, Kappa2 CrA's brightness is diminished by 0.45 magnitudes due to interstellar dust. This is an ordinary B-type main-sequence star with a stellar classification of B9Vnn, with the nn meaning extremely nebulous absorption lines, usually due to rapid rotation. It has 3.12 times the mass of the Sun and a radius 5.28 times larger than the Sun, which is large for stars of this type. It radiates 460 times the luminosity of the Sun from its photosphere at an effective tem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 binary system of stars in mutual orbit, gravitationally bound to each other) or is an ''optical double'', a chance line-of-sight alignment of two stars at different distances from the observer. Binary stars are important to stellar astronomers as knowledge of their motions allows direct calculation of stellar mass and other stellar parameters. The only (possible) case of "binary star" whose two components are separately visible to the naked eye is the case of Mizar and Alcor (though actually a multiple-star system), but it is not known for sure whether Mizar and Alcor are gravitationally bound. Since the beginning of the 1780s, both professional and amateur double star observers have telescopically measured the distances and angles between d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Herschel
Sir John Frederick William Herschel, 1st Baronet (; 7 March 1792 – 11 May 1871) was an English polymath active as a mathematician, astronomer, chemist, inventor, experimental photographer who invented the blueprint and did botanical work. Herschel originated the use of the Julian day system in astronomy. He named seven moons of Saturn and four moons of Uranus – the seventh planet, discovered by his father Sir William Herschel. He made many contributions to the science of photography, and investigated colour blindness and the chemical power of ultraviolet rays. His ''Preliminary Discourse'' (1831), which advocated an inductive approach to scientific experiment and theory-building, was an important contribution to the philosophy of science. Early life and work on astronomy Herschel was born in Slough, Buckinghamshire, the son of Mary Baldwin and astronomer William Herschel. He was the nephew of astronomer Caroline Herschel. He studied shortly at Eton College an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angular Separation
Angular distance \theta (also known as angular separation, apparent distance, or apparent separation) is the angle between the two sightlines, or between two point objects as viewed from an observer. Angular distance appears in mathematics (in particular geometry and trigonometry) and all natural sciences (e.g. astronomy and geophysics). In the classical mechanics of rotating objects, it appears alongside angular velocity, angular acceleration, angular momentum, moment of inertia and torque. Use The term ''angular distance'' (or ''separation'') is technically synonymous with ''angle'' itself, but is meant to suggest the linear distance between objects (for instance, a couple of stars observed from Earth). Measurement Since the angular distance (or separation) is conceptually identical to an angle, it is measured in the same units, such as degrees or radians, using instruments such as goniometers or optical instruments specially designed to point in well-defined directions and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Position Angle
In astronomy, position angle (usually abbreviated PA) is the convention for measuring angles on the sky. The International Astronomical Union defines it as the angle measured relative to the north celestial pole (NCP), turning positive into the direction of the right ascension. In the standard (non-flipped) images, this is a counterclockwise measure relative to the axis into the direction of positive declination. In the case of observed visual binary stars, it is defined as the angular offset of the secondary star from the primary relative to the north celestial pole. As the example illustrates, if one were observing a hypothetical binary star with a PA of 135°, that means an imaginary line in the eyepiece drawn from the north celestial pole to the primary (P) would be offset from the secondary (S) such that the angle would be 135°. When graphing visual binaries, the NCP is, as in the illustration, normally drawn from the center point (origin) that is the Primary downward&nd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corona Australis
Corona Australis is a constellation in the Southern Celestial Hemisphere. Its Latin name means "southern crown", and it is the southern counterpart of Corona Borealis, the northern crown. It is one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations. The Ancient Greeks saw Corona Australis as a wreath rather than a crown and associated it with Sagittarius (constellation), Sagittarius or Centaurus. Other cultures have likened the pattern to a turtle, ostrich nest, a tent, or even a hut belonging to a rock hyrax. Although fainter than its northern counterpart, the oval- or horseshoe-shaped pattern of its brighter stars renders it distinctive. Alpha Coronae Australis, Alpha and Beta Coronae Australis are the two brightest stars with an apparent magnitude of around 4.1. Epsilon Coronae Australis is the brightest example of a W Ursae Majoris variable in the southern sky. Lying alongside the Milky Way, Corona Australi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
