|
List Of Variable Stars
, there are over 52,011 known variable stars, with more being discovered regularly, so a complete list of every single variable is impossible at this place (cf. GCVS). The following is a list of variable stars that are well-known, bright, significant, or otherwise interesting. Notes References *David H. Levy, ''Observing variable stars : a guide for the beginner'' General Catalogue of Variable Stars See also * Lists of astronomical objects * Lists of stars * List of semiregular variable stars * List of stars that have unusual dimming periods A list is a set of discrete items of information collected and set forth in some format for utility, entertainment, or other purposes. A list may be memorialized in any number of ways, including existing only in the mind of the list-maker, but ... {{Variable star topics * Variable ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Variable Star
A variable star is a star whose brightness as seen from Earth (its apparent magnitude) changes systematically with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are classified as either: * ''Intrinsic variables'', whose luminosity actually changes periodically; for example, because the star swells and shrinks. * ''Extrinsic variables'', whose apparent changes in brightness are due to changes in the amount of their light that can reach Earth; for example, because the star has an orbiting companion that sometimes eclipses it. Many, possibly most, stars exhibit at least some oscillation in luminosity: the energy output of the Sun, for example, varies by about 0.1% over an 11-year solar cycle. Discovery An ancient Egyptian calendar of lucky and unlucky days composed some 3,200 years ago may be the oldest preserved historical document of the discovery of a variable star, the eclipsing binary Algol. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edward Pigott
Edward Pigott (1753–1825) was an English astronomer notable for being one of the founders of the study of variable stars. Biography Son of the astronomer Nathaniel Pigott, Pigott's work focused on variable stars. Educated in France with a mother from Louvain, the family moved to York in 1781. Despite their significant age difference, he was a friend and collaborator of John Goodricke (his distant cousin) until the latter's untimely death at the age of 21 in 1786. In 1784, Pigott informed the Royal Society of his discovery of a new variable star. This was Eta Aquilae which he had identified the previous year. He corresponded with leading astronomers of the day including William Herschel and Nevil Maskelyne. Pigott moved to Bath in 1796. Pigott's notebooks survive aYork City Archives Honors Asteroid 10220 Pigott is named after Edward and his father. It was discovered by R. A. Tucker at the observatory in Tucson, Arizona Tucson (; ; ) is a city in Pima County ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epsilon Aurigae
Epsilon Aurigae is a multiple star system in the northern constellation of Auriga, the charioteer. Its name is a Bayer designation that is Latinized from ε Aurigae, and abbreviated Epsilon Aur or ε Aur. It is an unusual eclipsing binary system comprising an F0 supergiant and a companion which is generally accepted to be a huge dark disk orbiting an unknown object, possibly a binary system of two dwarf B-type stars. The primary component is officially named Almaaz, pronounced , the traditional name for the system. The distance to the system is still a subject of debate, but data from the Gaia spacecraft puts its distance at around light years from Earth. Epsilon Aurigae was first suspected to be a variable star when German astronomer Johann Heinrich Fritsch observed it in 1821. Later observations by Eduard Heis and Friedrich Wilhelm Argelander reinforced Fritsch's initial suspicions and attracted attention to the star. Hans Ludendorff, however, was the first ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
U Arietis
U, or u, is the twenty-first letter and the fifth vowel letter of the Latin alphabet, used in the modern English alphabet and the alphabets of other western European languages and others worldwide. Its name in English is ''u'' (pronounced ), plural ''ues''. Name In English, the name of the letter is the "long U" sound, pronounced . In most other languages, its name matches the letter's pronunciation in open syllables. History U derives from the Semitic waw, as does F, and later, Y, W, and V. Its oldest ancestor goes back to Egyptian hieroglyphs, and is probably from a hieroglyph of a mace or fowl, representing the sound or the sound . This was borrowed to Phoenician, where it represented the sound , and seldom the vowel . In Greek, two letters were adapted from the Phoenician waw. The letter was adapted, but split in two, with Digamma or wau being adapted to represent , and the second one being Upsilon , which was originally adapted to represent , later fronte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aries (constellation)
Aries is one of the constellations of the zodiac. It is located in the Northern celestial hemisphere between Pisces (constellation), Pisces to the west and Taurus (constellation), Taurus to the east. The name Aries is Latin for sheep, ram. Its traditional astrological symbol is (♈︎). It is one of the 48 constellations described by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations. It is a mid-sized constellation ranking 39th in overall size, with an area of 441 square degrees (1.1% of the celestial sphere). Aries has represented a ram since late Babylonian times. Before that, the stars of Aries formed a farmhand. Different cultures have incorporated the stars of Aries into different constellations including twin inspectors in China and a porpoise in the Marshall Islands. Aries is a relatively dim constellation, possessing only four bright stars: Hamal (Alpha Arietis, second magnitude), Sheratan (Beta Arietis, third magnitude), Mesarthim ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
R Arietis
R, or r, is the eighteenth letter of the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''ar'' (pronounced ), plural ''ars''. The letter is the eighth most common letter in English and the fourth-most common consonant, after , , and . Name The name of the letter in Latin was (), following the pattern of other letters representing continuants, such as , , , , and . This name is preserved in French and many other languages. In Middle English, the name of the letter changed from to , following a pattern exhibited in many other words such as ''farm'' (compare French ) and ''star'' (compare German ). In Hiberno-English, the letter is called or , somewhat similar to ''oar'', ''ore'', ''orr''. The letter R is sometimes referred to as the 'canine letter', often rendered in English as the dog's letter. This Latin term referred to the Latin that was trilled to sound lik ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ara (constellation)
Ara (Latin for "the Altar") is a southern constellation between Scorpius, Telescopium, Triangulum Australe, and Norma. It was (as ) one of the Greek bulk (namely 48) described by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations designated by the International Astronomical Union. The orange supergiant Beta Arae, to us its brightest star measured with near-constant apparent magnitude of 2.85, is marginally brighter than blue-white Alpha Arae. Seven star systems are known to host planets. Sunlike Mu Arae hosts four known planets. Gliese 676 is a (gravity-paired) binary red dwarf system with four known planets. The Milky Way crosses the northwestern part of Ara. Within the constellation is Westerlund 1, a super star cluster that contains the red supergiant Westerlund 1-26, one of the largest stars known. History In ancient Greek mythology, Ara was identified as the altar where the gods first made offerings and formed an alliance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
U Arae
U, or u, is the twenty-first letter and the fifth vowel letter of the Latin alphabet, used in the modern English alphabet and the alphabets of other western European languages and others worldwide. Its name in English is ''u'' (pronounced ), plural ''ues''. Name In English, the name of the letter is the "long U" sound, pronounced . In most other languages, its name matches the letter's pronunciation in open syllables. History U derives from the Semitic waw, as does F, and later, Y, W, and V. Its oldest ancestor goes back to Egyptian hieroglyphs, and is probably from a hieroglyph of a mace or fowl, representing the sound or the sound . This was borrowed to Phoenician, where it represented the sound , and seldom the vowel . In Greek, two letters were adapted from the Phoenician waw. The letter was adapted, but split in two, with Digamma or wau being adapted to represent , and the second one being Upsilon , which was originally adapted to represent , later fronte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T Aquarii
T, or t, is the twentieth letter of the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''tee'' (pronounced ), plural ''tees''. It is derived from the Semitic Taw 𐤕 of the Phoenician and Paleo-Hebrew script (Aramaic and Hebrew Taw ת/𐡕/, Syriac Taw ܬ, and Arabic ت Tāʼ) via the Greek letter τ (tau). In English, it is most commonly used to represent the voiceless alveolar plosive, a sound it also denotes in the International Phonetic Alphabet. It is the most commonly used consonant and the second-most commonly used letter in English-language texts. History ''Taw'' was the last letter of the Western Semitic and Hebrew alphabets. The sound value of Semitic ''Taw'', the Greek alphabet Tαυ (''Tau''), Old Italic and Latin T has remained fairly constant, representing in each of these, and it has also kept its original basic shape in most of these alphabets. Us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karl Ludwig Harding
Karl Ludwig Harding (29 September 1765 – 31 August 1834) was a German astronomer, who discovered 3 Juno, Juno, the third asteroid of the main-belt in 1804. Life and career Harding was born in Lauenburg. From 1786–1789, he was educated at the University of Göttingen, where he studied theology, mathematics, and physics. In 1796, Johann Hieronymus Schröter hired Harding as a tutor for his son. Schröter was an enthusiastic astronomer and owner of a well-equipped observatory in Lilienthal, Lower Saxony, Lilienthal near Bremen, where Harding was soon appointed observer and inspector. In 1800, he was among the 24 astronomers invited to participate in the celestial police, a group dedicated to finding additional planets in the Solar System. As part of the group, in 1804, Harding discovered Juno at Schröter's observatory. In the next year he left Lilienthal, where his successor became Friedrich Bessel, Friedrich Wilhelm Bessel, as he was appointed extraordinary professor of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquarius (constellation)
Aquarius is an celestial equator, equatorial constellation of the zodiac, between Capricornus and Pisces (constellation), Pisces. Its name is Latin for "water-carrier" or "cup-carrier", and its old astronomical symbol is (♒︎), a representation of water. Aquarius is one of the oldest of the recognized constellations along the zodiac (the Sun's apparent path). It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the IAU designated constellations, 88 modern constellations. It is found in a region often called the Sea (astronomy), Sea due to its profusion of constellations with watery associations such as Cetus the whale, Pisces the fish, and Eridanus (constellation), Eridanus the river. At apparent magnitude 2.9, Beta Aquarii is the brightest star in the constellation. History and mythology Aquarius is identified as "The Great One" in the Babylonian star catalogues and represents the god Ea (god), Ea himself, who is commonl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
R Aquarii
R Aquarii (R Aqr) is a variable star in the constellation Aquarius. R Aquarii is a symbiotic star believed to contain a white dwarf and a Mira-type variable in a binary system. The orbital period is approximately 44 years. The main Mira-type star is a red giant, and varies in brightness by a factor of several hundred and with a period of slightly more than a year; this variability was discovered by Karl Ludwig Harding in 1810. It has a distance of about 218 parsecs, and is one of the nearest symbiotic stars and a well-known jet source. The two components have been resolved at a separation of 55 mas. By its gravitational pull, the white dwarf draws in material from the red giant and occasionally ejects some of the surplus in loops to form the nebula seen in the linked image. The whole system appears reddened because it is situated in a very dusty region of space, and its blue light is absorbed before reaching Earth. The nebula around R Aquarii is also known as Ceder ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
