Cygnus (constellation)
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| Abbreviation: | Cyg |
| Genitive: | Cygni |
| Symbology: | the Swan or The Northern Cross |
| Right ascension: | 20.62 h |
| Declination: | +42.03° |
| Area: | 804 sq. deg. (16th) |
| Main stars: | 9 |
| Bayer/Flamsteed stars: | 80 |
| Stars with known planets: | 5 |
| Bright stars: | 6 |
| Nearby stars: | 1 |
| Brightest star: | Deneb (α Cyg) (1.25m) |
| Nearest star: | 61 Cyg (11.4 ly) |
| Messier objects: | 2 |
| Meteor showers: | October Cygnids Kappa Cygnids |
| Bordering constellations: | Cepheus Draco Lyra Vulpecula Pegasus Lacerta |
| Visible at latitudes between +90° and −40° Best visible at 21:00 (9 p.m.) during the month of September |
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Cygnus (IPA: /ˈsɪgnəs/, Latin: swan) is a northern constellation. It was one of Ptolemy's 48 constellations, and is also one of the 88 modern constellations. Because of the pattern of its main stars, it is sometimes known as the Northern Cross (in contrast to the Southern Cross).
The bird extends over the Milky Way, appearing to fly south.
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[edit] Notable features
Cygnus contains several bright stars.
Deneb, α Cygni, is an extremely brilliant star, very prominent despite its distance (3230 light years). The blue supergiant forms the swan's tail, the upper end of the Northern Cross, and one of the vertices of the Summer Triangle asterism. Its also the 18th brightest star in the sky.
Albireo, β Cygni, is at the swan's beak. It is one of the most beautiful double stars of the sky, a golden star easily distinguishable in a small telescope from its blue companion.
Another interesting star is 61 Cygni. In 1838, this star had the highest known proper motion of any star in the sky; this was taken as evidence that it was relatively nearby and it was accordingly chosen as the first star (other than the Sun) to have its distance measured. It is 11.4 light years away, one of the closest stars to our solar system.
The star 16 Cygni B is an extrasolar planetary system with one confirmed planet 1.5 times the mass of Jupiter.
The star HD 188753 A in Cygnus has an extrasolar planet called HD 188753 Ab which was the first planet discovered in a 3-sun (triple star) system.
Cygnus also contains the X-ray source Cygnus X-1, which is considered to be one of the most likely black hole candidates.
In addition, Cygnus has a variety of variable stars, including XX Cyg and V508 Cyg.
[edit] Notable deep sky objects
Several star clusters and nebulae are found in Cygnus due to its position on the Milky Way. The North America Nebula (NGC 7000) is found a bit to the east of Deneb. Its resemblance to the continent is best appreciated in photographs. The Pelican Nebula (IC 5070) is nearby.
More supernovae have been seen in the Fireworks Galaxy (NGC 6946) than in any other galaxy.
[edit] History and mythology
The constellation bears a resemblance to a wide winged, long necked bird, in graceful flight [1]. In Greek mythology, the constellation represents several different legendary swans. Zeus disguised himself as a swan to seduce Leda, who gave birth to the Gemini, Helen of Troy, and Clytemnestra.
Orpheus was transformed into a swan after his murder, and was said to have been placed in the sky next to his lyre (Lyra).
Finally, it is said that a youth named Cygnus was the lover of the ill-fated Phaethon. After Phaethon was killed trying to drive the chariot of the sun, Cygnus searched desperately for his body in the river Eridanus where it had fallen. He dove so many times into the river that Zeus took pity on him and changed him into the waterbird that has since borne his name.
Cygnus, together with other constellations in the Zodiac sign of Sagittarius (specifically Lyra and Aquila, together with Sagittarius itself), may be a significant part of the origin of the myth of the Stymphalian Birds, one of The Twelve Labours of Heracles.
In Chinese mythology, the constellation Cygnus is the site of the once-a-year magpie bridge (鹊桥, Que Qiao) which connects the lovers Niu Lang and Zhi Nu (see Qi Xi).
[edit] See also
| The 88 modern Constellations |
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| Andromeda • Antlia • Apus • Aquarius • Aquila • Ara • Aries • Auriga • Boötes • Caelum • Camelopardalis • Cancer • Canes Venatici • Canis Major • Canis Minor • Capricornus • Carina • Cassiopeia • Centaurus • Cepheus • Cetus • Chamaeleon • Circinus • Columba • Coma Berenices • Corona Australis • Corona Borealis • Corvus • Crater • Crux • Cygnus • Delphinus • Dorado • Draco • Equuleus • Eridanus • Fornax • Gemini • Grus • Hercules • Horologium • Hydra • Hydrus • Indus • Lacerta • Leo • Leo Minor • Lepus • Libra • Lupus • Lynx • Lyra • Mensa • Microscopium • Monoceros • Musca • Norma • Octans • Ophiuchus • Orion • Pavo • Pegasus • Perseus • Phoenix • Pictor • Pisces • Piscis Austrinus • Puppis • Pyxis • Reticulum • Sagitta • Sagittarius • Scorpius • Sculptor • Scutum • Serpens • Sextans • Taurus • Telescopium • Triangulum • Triangulum Australe • Tucana • Ursa Major • Ursa Minor • Vela • Virgo • Volans • Vulpecula |
[edit] External links
![[1]](http://borghetto.astrofili.org/costellazioni/cygnus.JPG){kind=link}