Editing Cygnus (constellation) (section)

== Characteristics ==
A very large constellation, Cygnus is bordered by Cepheus to the north and east, Draco to the north and west, Lyra to the west, Vulpecula to the south, Pegasus to the southeast and Lacerta to the east. The three-letter abbreviation for the constellation, as adopted by the IAU in 1922, is "Cyg".<ref name=pa30_469>{{cite journal |last=Russell |first=Henry Norris |author-link=Henry Norris Russell |title=The New International Symbols for the Constellations |journal=Popular Astronomy |volume=30 |page=469 |bibcode=1922PA.....30..469R |year=1922}}</ref> The official constellation boundaries, as set by Belgian astronomer [[Eugène Joseph Delporte|Eugène Delporte]] in 1930, are defined as a polygon of 28 segments. In the [[equatorial coordinate system]], the [[right ascension]] coordinates of these borders lie between {{RA|19|07.3}} and {{RA|22|02.3}}, while the [[declination]] coordinates are between 27.73° and 61.36°.<ref name=boundary>{{cite web |title=Cygnus, Constellation Boundary |website=The Constellations |url=https://www.iau.org/public/themes/constellations/#cyg |access-date=9 December 2013}}</ref> Covering 804 square degrees and around 1.9% of the night sky, Cygnus ranks 16th of the 88 constellations in size.<ref name="thompson07">{{cite book |last=Thompson |first=Robert |author2=Thompson, Barbara |title=Illustrated Guide to Astronomical Wonders: From Novice to Master Observer |publisher=O'Reilly Media |location=Sebastopol, California |date=2007 |pages=214–15 |isbn=978-0-596-52685-6 |url=https://books.google.com/books?id=ymt9nj_uPhwC&pg=PA214}}</ref>

Cygnus [[Culmination|culminates]] at midnight on 29 June, and is most visible in the evening from the early summer to mid-autumn in the Northern Hemisphere.<ref name="thompson07"/>

Normally, Cygnus is depicted with Delta and Epsilon Cygni as its wings. [[Deneb]], the brightest in the constellation is at its tail, and Albireo as the tip of its beak.{{sfn|Ridpath|Tirion|2001|pp=134–137}}

There are several [[Asterism (astronomy)|asterisms]] in Cygnus. In the 17th-century German celestial cartographer [[Johann Bayer]]'s star atlas the ''Uranometria'', Alpha, Beta and Gamma Cygni form the pole of a cross, while Delta and Epsilon form the cross beam. The nova P Cygni was then considered to be the body of Christ.<ref name=wagman>{{cite book |last=Wagman |first=Morton |year=2003 |title=Lost Stars: Lost, Missing and Troublesome Stars from the Catalogues of Johannes Bayer, Nicholas Louis de Lacaille, John Flamsteed, and Sundry Others |publisher=The McDonald & Woodward Publishing Company |location=Blacksburg, Virginia |isbn=978-0-939923-78-6 |page=131}}</ref>