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'{{Infobox constellation | name = Draco | abbreviation = Dra | genitive = Draconis | pronounce = {{plainlist | * {{IPAc-en|ˈ|d|r|eɪ|k|oʊ}} * genitive {{IPAc-en|d|r|ə|ˈ|k|oʊ|n|ɨ|s}} }} | symbolism = the [[Dragon]] | RA = 17 | dec= +65 | family = [[Ursa Major Family|Ursa Major]] | quadrant = NQ3 | areatotal = 1083 | arearank = 8th | numbermainstars = 14 | numberbfstars = 76 | numberstarsplanets = 18 | numberbrightstars = 3 | numbernearbystars = 7 | brighteststarname = [[Gamma Draconis|γ Dra]] (Eltanin) | starmagnitude = 2.24 | neareststarname = [[Struve 2398]] | stardistancely = 11.52 | stardistancepc = 3.53 | numbermessierobjects = 1 | meteorshowers = [[Draconids]] | bordering = {{plainlist | * [[Boötes]] * [[Hercules (constellation)|Hercules]] * [[Lyra]] * [[Cygnus (constellation)|Cygnus]] * [[Cepheus (constellation)|Cepheus]] * [[Ursa Minor]] * [[Camelopardalis]] * [[Ursa Major]] }} | latmax = [[North Pole|90]] | latmin = [[15th parallel south|15]] | month =all year | notes = leah is awesome }} '''Draco''' is a [[constellation]] in the far northern sky. Its name is [[Latin]] for [[dragon]]. Draco is [[circumpolar star|circumpolar]] (that is, never setting) for many observers in the [[northern hemisphere]]. It was one of the 48 constellations listed by the 2nd century astronomer [[Ptolemy]], and remains one of the 88 modern constellations today. The north pole of the [[ecliptic]] is in Draco.{{sfn|Ridpath|Tirion|2001|pp=142-143}} == Notable features == [[Image:DracoCC.jpg|thumb|left|200px|The constellation Draco as it can be seen by the naked eye.]] === Stars === {{main|List of stars in Draco}} [[Thuban]] (α Draconis) was the northern [[pole star]] from 3942 BC, when it moved farther north than Theta Boötis, until 1793 BC. The [[Egyptian Pyramids]] were designed to have one side facing north, with an entrance passage designed so that Thuban would be visible at night.{{sfn|Staal|1988|pp=239–240}} Due to the effects of [[Axial precession (astronomy)|precession]], it will once again be the pole star around the year 21000 AD.<!-- not cited to Ridpath & Tirion 2001 --> It is a blue-white giant star of magnitude 3.7, 309 light-years from Earth. The traditional name of Alpha Draconis, Thuban, means "head of the serpent".{{sfn|Ridpath|Tirion|2001|pp=142-143}} There are two other stars above magnitude 3 in Draco. The brighter of the two&mdash;and the brightest star in Draco&mdash;is [[Gamma Draconis]], traditionally called Etamin or Eltanin. It is an orange giant star of magnitude 2.2, 148 light-years from Earth. The [[aberration of starlight]] was discovered in 1728 when [[James Bradley]] observed Gamma Draconis. [[Beta Draconis]], traditionally called Rastaban, is a yellow giant star of magnitude 2.8, 362 light-years from Earth. Its name shares a meaning with Thuban, "head of the serpent".{{sfn|Ridpath|Tirion|2001|pp=142-143}} Draco is home to several double stars and binary stars. [[Eta Draconis|η Draconis]] is a [[double star]] with a yellow-hued primary of magnitude 2.8 and a white-hued secondary of magnitude 8.2 located south of the primary. The two are separated by 4.8 [[arcsecond]]s.<ref name="French"/> [[Mu Draconis]], traditionally called Alrakis, is a [[binary star]] with two white components. Magnitude 5.6 and 5.7, the two components orbit each other every 670 years. The Alrakis system is 88 light-years from Earth. [[Nu Draconis]] is a similar binary star with two white components, 100 light-years from Earth. Both components are of magnitude 4.9 and can be distinguished in a small amateur telescope or a pair of binoculars. [[Omicron Draconis]] is a double star divisible in small telescopes. The primary is an orange giant of magnitude 4.6, 322 light-years from Earth. The secondary is of magnitude 7.8. [[Psi Draconis]] is a binary star divisible in binoculars and small amateur telescopes, 72 light-years from Earth. The primary is a yellow-white star of magnitude 4.6 and the secondary is a yellow star of magnitude 5.8. [[16 Draconis]] and [[17 Draconis]] are part of a triple star 400 light-years from Earth, divisible in medium-sized amateur telescopes. The primary, a blue-white star of magnitude 5.1, is itself a binary with components of magnitude 5.4 and 6.5. The secondary is of magnitude 5.5 and the system is 400 light-years away.{{sfn|Ridpath|Tirion|2001|pp=142-143}} [[20 Draconis]] is a binary star with a white-hued primary of magnitude 7.1 and a yellow-hued secondary of magnitude 7.3 located east-northeast of the primary. The two are separated by 1.2 arcseconds at their maximum and have an orbital period of 420 years. As of 2012, the two components are approaching their maximum separation.<ref name="French"/> [[39 Draconis]] is a triple star 188 light-years from Earth, divisible in small amateur telescopes. The primary is a blue star of magnitude 5.0, the secondary is a yellow star of magnitude 7.4, and the tertiary is a star of magnitude 8.0; the tertiary appears to be a close companion to the primary. [[40 Draconis]] and [[41 Draconis]] are a binary star divisible in small telescopes. The two orange dwarf stars are 170 light-years from Earth and are of magnitude 5.7 and 6.1.{{sfn|Ridpath|Tirion|2001|pp=142-143}} [[R Draconis]] is a red [[Mira variable|Mira-type variable star]] with a period of about 8 months. Its average minimum magnitude is approximately 12.4, and its average maximum magnitude is approximately 7.6. It was discovered to be a variable star by [[Hans Geelmuyden]] in 1876.<ref name="MacRobert"/> The constellation contains the star recently named [[Kepler-10]] which has been confirmed to be orbited by [[Kepler-10b]], the smallest ever rocky Earth-sized planet detected outside of our solar system. === Deep-sky objects === One of the [[deep-sky object]]s in Draco is the [[Cat's Eye Nebula]] (NGC 6543), a [[planetary nebula]] approximately 3,000 light-years away that was discovered by English astronomer [[William Herschel]] in 1786.<ref name="French"/> It is 9th magnitude and was named for its appearance in the [[Hubble Space Telescope]], though it appears as a fuzzy blue-green disk in an amateur telescope.{{sfn|Ridpath|Tirion|2001|pp=142-143}} NGC 6543 has a very complex shape due to gravitational interactions between the components of the [[multiple star]] at its center, the progenitor of the nebula approximately 1,000 years ago.{{sfn|Wilkins|Dunn|2006}} It is located 9.6 [[arcminute]]s away from the [[north ecliptic pole]] to the west-northwest. It is also related to [[IC 4677]], a nebula that appears as a bar 1.8 arcminutes to the west of the Cat's Eye nebula. In long-term exposures, IC 4677 appears as a portion of a ring surrounding the planetary nebula.<ref name="French"/> There are several faint [[galaxy|galaxies]] in Draco, one of which is the [[lenticular galaxy]] [[NGC 5866]], sometimes considered to be [[Messier Object 102]]. Another is the [[Draco Dwarf Galaxy]], one of the least luminous galaxies with an [[absolute magnitude]] of −8.6 and a diameter of only about 3,500 [[light year]]s, discovered by Albert G. Wilson of [[Lowell Observatory]] in 1954. Another dwarf galaxy found in this constellation is [[PGC 39058]]. [[File:PGC 39058.jpg|thumb|right|300px|[[PGC 39058]], a dwarf galaxy found within the Draco constellation&nbsp;– picture taken by ESA/Hubble & NASA.]] Draco also features several [[interacting galaxy|interacting galaxies]] and [[galaxy cluster]]s. One such massive cluster is [[Abell 2218]], located at a distance of 3 billion light-years ([[redshift]] 0.171). It acts as a [[gravitational lensing|gravitational lens]] for even more distant background galaxies, allowing astronomers to study those galaxies as well as Abell 2218 itself; more specifically, the lensing effect allows astronomers to confirm the cluster's mass as determined by [[x-ray]] emissions. One of the most well-known [[interacting galaxy|interacting galaxies]] is [[Arp 188]], also called the "Tadpole Galaxy". Named for its appearance, which features a "tail" of stars 280,000 light-years long, the Tadpole Galaxy is at a distance of 420 million light-years (redshift 0.0314). The tail of stars drawn off the Tadpole Galaxy appears blue because the gravitational interaction disturbed [[nebula|clouds of gas]] and sparked [[star formation]].{{sfn|Wilkins|Dunn|2006}} [[Q1634+706]] is a [[quasar]] that holds the distinction of being the most distant object usually visible in an amateur telescope. At magnitude 14.4, it appears starlike, though it is at a distance of 12.9 billion light-years. The light of Q1634+706 has taken 8.6 billion years to reach Earth, a discrepancy attributable to the [[expansion of the universe]].<ref name="French"/> === Mythology === [[File:Dracourania.jpg|thumb|left|300px|Draco coils around the north celestial pole, as depicted in Urania's Mirror, a set of constellation cards published in London c.1825]] Dragons in Greek mythology that may have inspired the constellation's name include [[Dragons in Greek mythology|Ladon]], the dragon who guarded the golden apples of the [[Hesperides#The Garden of the Hesperides|Hesperides]].{{sfn|Staal|1988|p=237}} [[Hercules]] killed Ladon during his [[labors of Hercules|12 labors]]; he was tasked with stealing the golden apples. [[Hercules (constellation)|The constellation of Hercules]] is depicted near Draco.{{sfn|Ridpath|Tirion|2001|pp=142-143}} In Greco- Roman legend, Draco was a dragon killed by the goddess [[Minerva]] and tossed into the sky upon his defeat. The dragon was one of the [[Giant Titans]], who battled the Olympic gods for ten years. As Minerva threw the dragon, it became twisted on itself and froze at the cold [[North Celestial Pole]] before it could right itself.{{sfn|Staal|1988|p=237}} Sometimes, Draco is represented as the demon son of [[Gaia (mythology)|Gaia]], [[Typhon]].{{sfn|Staal|1988|p=237}} Traditional Arabic astronomy does not depict a dragon in modern-day Draco, which is called the [[Mother Camels]]. Instead, two [[hyena]]s, represented by [[Eta Draconis]] and [[Zeta Draconis]] are seen attacking a baby camel (a dim star near [[Beta Draconis]]), which is protected by four female camels, represented by [[Beta Draconis]], [[Gamma Draconis]], [[Nu Draconis]], and [[Xi Draconis]]. The nomads who own the camels are camped nearby, represented by a cooking tripod composed of [[Upsilon Draconis|Upsilon]], [[Tau Draconis|Tau]], and [[Sigma Draconis]].{{sfn|Staal|1988|p=239}} === Meteor showers === The [[February Eta Draconids]] are a meteor shower that was discovered on February 4, 2011. Observers noted six meteors with a common [[radiant (meteor shower)|radiant]] in a short period. Its parent is a previously unknown [[long-period comet]].<ref>{{cite journal |journal = Sky & Telescope |date = September 2012 |last = Jenniskens |first = Peter |page = 24 |title = Mapping Meteoroid Orbits: New Meteor Showers Discovered}}</ref> == Namesakes == [[USS Draco (AK-79)]] was a [[United States Navy]] [[Crater class cargo ship]] named after the constellation. The main character in the 1996 film ''[[Dragonheart]]'' gets his name from this constellation. The film also reveals that Draco is actually a dragon heaven, where dragons go when they die if they have upheld the oath of an ancient dragon to guard mankind, with dragons otherwise fading into nothing upon their deaths. At the conclusion of the film, Draco, the last dragon, ascends into the constellation after he sacrifices himself to destroy an evil king that he had saved years ago. The chess opening called the [[Sicilian Defence, Dragon Variation|Dragon Variation]] of the Sicilian Defense was also named after the constellation by Russian chess master [[Fyodor Dus-Chotimirsky]]. [[J.K. Rowling]] named the character [[Draco Malfoy]] after the constellation in her [[Harry Potter (series)|''Harry Potter'' book series]]. The [[Beyblade]] Lightning L-Drago 100HF and its evolutions Meteo L-Drago LW105LF and L-Drago Destructor F:S are inspired by/based on the Draco constellation. They all feature three dragon heads chasing each other in a counter-clockwise motion, possibly referencing Ladon's multiple heads. == References == '''Citations''' {{reflist | refs = <ref name="French"> {{cite journal | last = French | first = Sue | date = July 2012 | title = By Draco's Scaly Folds | journal = Sky & Telescope | volume = 124 | issue = 1 }} </ref> <ref name="MacRobert"> {{cite journal | last = MacRobert | first = Alan | date = July 2012 | title = The Rise of R Draconis | journal = Sky & Telescope | volume = 124 | issue = 1 }} </ref> }} '''References''' * {{citation |title = Stars and Planets Guide |last1 = Ridpath |first1 = Ian |last2 = Tirion |first2 = Wil |year = 2001 |publisher = Princeton University Press |isbn = 0-691-08913-2}} * {{cite book | last1 = Ridpath | first1 = Ian | last2 = Tirion | first2 = Wil | year = 2007 | title = Stars and Planets Guide | publisher = Princeton University Press | isbn = 978-0-691-13556-4 | ref = harv }} * {{cite book | last = Staal | first = Julius D.W. | year = 1988 | title = The New Patterns in the Sky | publisher = McDonald and Woodward Publishing Company | isbn = 978-0-939923-04-5 | ref = harv }} * {{cite book | last1 = Wilkins | first1 = Jamie | last2 = Dunn | first2 = Robert | year = 2006 | title = 300 Astronomical Objects: A Visual Reference to the Universe | publisher = Firefly Books | isbn = 978-1-55407-175-3 | ref = harv }} == External links == {{Commons and category|Draco|Draco (constellation)}} * [http://www.allthesky.com/constellations/draco/ The Deep Photographic Guide to the Constellations: Draco] * [http://www.ianridpath.com/startales/draco.htm Star Tales&nbsp;– Draco] * http://www.starryskies.com/The_sky/constellations/draco.html * [http://www.constellation-guide.com/constellation-list/draco-constellation/ Draco Constellation at Constellation Guide] {{Stars of Draco}} {{navconstel}} {{Sky|17|00|00|+|65|00|00|10}} {{DEFAULTSORT:Draco (Constellation)}} [[Category:Draco (constellation)| ]] [[Category:Constellations]] [[Category:Dragons]] [[Category:Northern constellations]] [[Category:Constellations listed by Ptolemy]]'