Editing Serpens (section)

== Characteristics ==
Serpens is the only one of the [[88 modern constellations]] to be split into two disconnected regions in the sky: ''Serpens Caput'' (the head) and ''Serpens Cauda'' (the tail). The constellation is also unusual in that it depends on another constellation for context; specifically, it is being held by the Serpent Bearer Ophiuchus.<ref name="Ridpath">{{cite web|url=http://www.ianridpath.com/startales/serpens.html |title=Serpens |work=Star Tales |last=Ridpath |first=Ian |publisher=self-published |access-date=15 May 2014}}</ref>

Serpens Caput is bordered by [[Libra (constellation)|Libra]] to the south, [[Virgo (constellation)|Virgo]] and [[Boötes]] to the west, [[Corona Borealis]] to the north, and Ophiuchus and [[Hercules (constellation)|Hercules]] to the east; Serpens Cauda is bordered by [[Sagittarius (constellation)|Sagittarius]] to the south, Scutum and [[Aquila (constellation)|Aquila]] to the east, and Ophiuchus to the north and west. Covering 636.9 [[square degree]]s total, it ranks 23rd of the 88 constellations in size. It appears prominently in both the northern and southern skies during the Northern Hemisphere's summer.<ref name=tirionconst>{{cite web| url=http://www.ianridpath.com/constellations1.html | title=Constellations: Andromeda–Indus | work= Star Tales |last=Ridpath |first=Ian |author-link=Ian Ridpath |publisher=self-published | access-date= 1 April 2014}}</ref> Its main [[asterism (astronomy)|asterism]] consists of 11 stars, and 108 stars in total are brighter than magnitude 6.5, the traditional limit for naked-eye visibility.<ref name=tirionconst/>

Serpens Caput's boundaries, as set by Belgian astronomer [[Eugène Joseph Delporte|Eugène Delporte]] in 1930, are defined by a 10-sided polygon, while Serpens Cauda's are defined by a 22-sided polygon. In the [[equatorial coordinate system]], the [[right ascension]] coordinates of Serpens Caput's borders lie between {{RA|15|10.4}} and {{RA|16|22.5}}, while the [[declination]] coordinates are between {{dec|25.66}} and {{dec|−03.72}}. Serpens Cauda's boundaries lie between right ascensions of {{RA|17|16.9}} and {{RA|18|58.3}} and declinations of {{dec|06.42}} and {{dec|−16.14}}.<ref name="boundary">{{cite journal | title=Serpens, Constellation Boundary | journal=The Constellations | publisher=International Astronomical Union | url=https://www.iau.org/public/themes/constellations/#ser|access-date=20 April 2014}}</ref> The [[International Astronomical Union]] (IAU) adopted the three-letter abbreviation "Ser" for the constellation in 1922.<ref name="boundary"/><ref name="pa30_469">{{cite journal | last=Russell | first=H. N.| title=The New International Symbols for the Constellations | journal=[[Popular Astronomy (US magazine)|Popular Astronomy]] | volume=30 |pages=469–71 |bibcode=1922PA.....30..469R | year=1922}}</ref>