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Pegasus (constellation)
Pegasus is a constellation in the northern sky, named after the winged horse Pegasus in Greek mythology. It was one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and is one of the IAU designated constellations, 88 constellations recognised today. With an apparent magnitude varying between 2.37 and 2.45, the brightest star in Pegasus is the orange supergiant Epsilon Pegasi, also known as Enif, which marks the horse's muzzle. Alpha Pegasi, Alpha (Markab), Beta Pegasi, Beta (Scheat), and Gamma Pegasi, Gamma (Algenib), together with Alpha Andromedae (Alpheratz) form the large Asterism (astronomy), asterism known as the ''Square of Pegasus''. Twelve star systems have been found to have exoplanets. 51 Pegasi was the first Sun-like star discovered to have an exoplanet companion. Mythology The Babylonian constellation IKU (field) had four stars of which three were later part of the Greek constellation ''Hippos'' (Pegasus). Pegasus, in Greek mythology, was a winge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wing
A wing is a type of fin that produces both Lift (force), lift and drag while moving through air. Wings are defined by two shape characteristics, an airfoil section and a planform (aeronautics), planform. Wing efficiency is expressed as lift-to-drag ratio, which compares the benefit of lift with the air resistance of a given wing shape, as it flies. Aerodynamics is the study of wing performance in air. Equivalent Foil (fluid mechanics), foils that move through water are found on Hydrofoil, hydrofoil power vessels and Sailing hydrofoil, foiling sailboats that lift out of the water at speed and on submarines that use diving planes to point the boat upwards or downwards, while running submerged. Hydrodynamics is the study of foil performance in water. Etymology and usage The word "wing" from the Old Norse ''vængr'' for many centuries referred mainly to the foremost limb (anatomy), limbs of birds (in addition to the architectural aisle). But in recent centuries the word's meaning ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greek Mythology
Greek mythology is the body of myths originally told by the Ancient Greece, ancient Greeks, and a genre of ancient Greek folklore, today absorbed alongside Roman mythology into the broader designation of classical mythology. These stories concern the ancient Greek religion's view of the Cosmogony, origin and Cosmology#Metaphysical cosmology, nature of the world; the lives and activities of List of Greek deities, deities, Greek hero cult, heroes, and List of Greek mythological creatures, mythological creatures; and the origins and significance of the ancient Greeks' cult (religious practice), cult and ritual practices. Modern scholars study the myths to shed light on the religious and political institutions of ancient Greece, and to better understand the nature of mythmaking itself. The Greek myths were initially propagated in an oral tradition, oral-poetic tradition most likely by Minoan civilization, Minoan and Mycenaean Greece, Mycenaean singers starting in the 18th century&n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medusa
In Greek mythology, Medusa (; ), also called Gorgo () or the Gorgon, was one of the three Gorgons. Medusa is generally described as a woman with living snakes in place of hair; her appearance was so hideous that anyone who looked upon her was Petrifaction in mythology and fiction, turned to stone. Medusa and her Gorgon sisters Euryale and Stheno were usually described as daughters of Phorcys and Ceto; of the three, only Medusa was mortal. Medusa was beheaded by the Greek hero Perseus, who then used her head, which retained its ability to turn onlookers to stone, as a weapon until he gave it to the goddess Athena to place on her Aegis, shield. In classical antiquity, the image of the head of Medusa appeared in the apotropaic magic, evil-averting device known as the ''Gorgoneion''. According to Hesiod and Aeschylus, she lived and died on Sarpedon, somewhere near Cisthene (Mysia), Cisthene. The 2nd-century BC novelist Dionysios Skytobrachion puts her somewhere in Ancient Libya, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perseus
In Greek mythology, Perseus (, ; Greek language, Greek: Περσεύς, Romanization of Greek, translit. Perseús) is the legendary founder of the Perseid dynasty. He was, alongside Cadmus and Bellerophon, the greatest Greek hero and slayer of monsters before the days of Heracles. He beheaded the Gorgon Medusa for Polydectes and saved Andromeda (mythology), Andromeda from the sea monster Cetus (mythology), Cetus. He was the son of Zeus and the mortal Danaë, as well as the half-brother and great-grandfather of Heracles (as they were both children of Zeus, and Heracles's mother was Perseus' granddaughter). Etymology Because of the obscurity of the name "Perseus" and the legendary character of its bearer, most etymologists presume that it might be pre-Greek; however, the name of Perseus's native city was Greek and so were the names of his wife and relatives. There is some idea that it descended into Greek from the Proto-Indo-European language. In that regard Robert Graves, Grave ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hippocrene
In Greek mythology, Hippocrene () is a spring on Mount Helicon. It was sacred to the Muses and was said to have formed when the winged horse Pegasus struck his hoof into the ground, whence its name which literally translates as "Steed/Horse's Fountain". The water was supposed to bring forth poetic inspiration when imbibed. Sources Hesiod refers to the horse's well on Helicon in his ''Theogony''. And after they have washed their tender skin in Permessus or ''Hippocrene'' or holy Olmeidus, they perform choral dances on highest ''Helicon'', beautiful, lovely ones, and move nimbly with their feet. Petrarch refers to the fountain of Helicon in his epic poem ''Africa'': Sisters who are my sweet care, If I sing to you of wonders, I pray that it be granted to me To drink again at the ''fountain of Helicon''. Camoens cites the fountain as a great source of poetic inspiration in his epic Portuguese poem '' The Lusiads,'' as translated: And you, my Tagian Nymphs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
51 Pegasi
51 Pegasi (abbreviated 51 Peg), formally named Helvetios , is a Sun-like star located from Earth in the constellation of Pegasus. It was the first main-sequence star found to have an exoplanet (designated 51 Pegasi b, officially named Dimidium) orbiting it. Properties The star's apparent magnitude is 5.49, making it visible with the naked eye under suitable viewing conditions. 51 Pegasi was listed as a standard star for the spectral type G2IV in the 1989 ''The Perkins catalog of revised MK types for the cooler stars''. Historically, it was generally given a stellar classification of G5V, and even in more modern catalogues it is usually listed as a main-sequence star. The NStars project assign it a G2V spectral class. It is generally considered to still be generating energy through the thermonuclear fusion of hydrogen at its core, but to be in a more evolved state than the Sun. The effective temperature of the chromosphere is about , giving 51 Pegasi the characteri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asterism (astronomy)
An asterism is an observational astronomy, observed pattern or group of stars in the sky. Asterisms can be any identified star pattern, and therefore are a more general concept than the IAU designated constellations, 88 formally defined constellations. Constellations are based upon asterisms, but unlike asterisms, constellations are defined regions with official boundaries which together encompass the entire sky. Asterisms range from simple shapes of just a few stars to more complex collections of many stars covering large portions of the sky. The stars themselves may be bright naked-eye objects or fainter, even telescopic, but they are generally all of a similar brightness to each other. The larger brighter asterisms are useful for people who are familiarizing themselves with the night sky. The patterns of stars seen in asterisms are not necessarily a product of any physical association between the stars, but are rather the result of the particular perspectives of their observ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha Andromedae
Alpheratz is a prominent star system in the constellation of Andromeda (constellation), Andromeda. Pronounced , it has the Bayer designation Alpha Andromedae, Latinisation of names, Latinised from α Andromedae, and abbreviated Alpha And or α And, respectively. Alpheratz is the brightest stars, brightest star in the constellation when Mirach (βAndromedae) undergoes its periodical dimming. Immediately northeast of the constellation of Pegasus (constellation), Pegasus, it is the upper left star of the Great Square of Pegasus. It is located at a distance of 97 light-years from Earth. Although it appears to the naked eye as a single star with overall apparent visual magnitude +2.06, it is actually a binary star, binary system composed of two stars in close orbit. The chemistry, chemical composition of the brighter of the two stars is unusual as it is a mercury-manganese star whose atmosphere contains abnormally high abundances of mercury (element), mercury, manganese, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamma Pegasi
Gamma Pegasi is a binary star in the constellation of Pegasus Pegasus (; ) is a winged horse in Greek mythology, usually depicted as a white stallion. He was sired by Poseidon, in his role as horse-god, and foaled by the Gorgon Medusa. Pegasus was the brother of Chrysaor, both born from Medusa's blood w ..., located at the southeast corner of the asterism (astronomy), asterism known as the Great Square. It has the formal name Algenib ; the Bayer designation Gamma Pegasi is Romanization of Greek, Latinized from γ Pegasi and abbreviated Gamma Peg or γ Peg. The average apparent visual magnitude of +2.84 makes this the List of stars in Pegasus, fourth-brightest star in the constellation. The distance to this system has been measured using the parallax technique, yielding a value of roughly . Nomenclature ''Gamma Pegasi'' is the star's Bayer designation. Although it also had the traditional name ''Algenib'', this name was also used for Alpha Persei. In 2016, the Inter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beta Pegasi
Beta Pegasi (β Pegasi, abbreviated Beta Peg, β Peg), formally named Scheat , is a red giant star and the second-brightest star (after Epsilon Pegasi) in the constellation of Pegasus. It forms the upper right corner of the Great Square of Pegasus, a prominent rectangular asterism. Nomenclature ''β Pegasi'' ( Latinised to ''Beta Pegasi'') is the star's Bayer designation. It bore the traditional name of ''Scheat'', a name that had also been used for Delta Aquarii. The name was derived from the Arabic ''Al Sā'id'' "the upper arm", or from ''Sa'd''. In 2016, the International Astronomical Union organised a Working Group on Star Names (WGSN) to catalog and standardise proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included ''Scheat'' for this star (the name ''Skat'' was later approved for Delta Aquarii). In Chinese, (), meaning '' Encampment'', refers to an asterism consi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha Pegasi
Alpha Pegasi (α Pegasi, abbreviated Alpha Peg, α Peg), formally named Markab , is the third-brightest star in the constellation of Pegasus and one of the four stars in the asterism known as the Great Square of Pegasus. Properties Alpha Pegasi has a stellar classification of A0 IV, indicating that it is an A-type subgiant star that has exhausted the hydrogen at its core and has evolved beyond the main sequence. Its spectrum has also been classified as B9V and B9.5III. It is rotating rapidly, with a projected rotational velocity of 130 km/s giving a lower bound on the azimuthal velocity along the star's equator. The effective temperature of the photosphere is about 10,000 K and the star has expanded to nearly five times the radius of the Sun, emitting 165 times as much energy as the sun. Nomenclature ''α Pegasi'' ( Latinised to ''Alpha Pegasi'') is the star's Bayer designation. It bore the traditional name ''Markab'' (or ''Marchab''), which derived fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apparent Magnitude
Apparent magnitude () is a measure of the Irradiance, brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction (astronomy), extinction of the object's light caused by interstellar dust along the sightline, line of sight to the observer. Unless stated otherwise, the word ''magnitude'' in astronomy usually refers to a celestial object's apparent magnitude. The magnitude scale likely dates to before the ancient Ancient Greek astronomy#Astronomy in the Greco-Roman and Late Antique eras, Roman astronomer Ptolemy, Claudius Ptolemy, whose Star catalogue, star catalog popularized the system by listing stars from First-magnitude star, 1st magnitude (brightest) to 6th magnitude (dimmest). The modern scale was mathematically defined to closely match this historical system by Norman Robert Pogson, Norman Pogson in 1856. The scale is reverse logarithmic scale, logarithmic: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
