Editing Cancer (constellation) (section)

== Characteristics ==
Cancer is a medium-sized constellation that is bordered by [[Gemini (constellation)|Gemini]] to the west, [[Lynx (constellation)|Lynx]] to the north, [[Leo Minor]] to the northeast, [[Leo (constellation)|Leo]] to the east, [[Hydra (constellation)|Hydra]] to the south, and [[Canis Minor]] to the southwest. The three-letter abbreviation for the constellation, as adopted by the [[International Astronomical Union]] in 1922, is "Cnc".<ref name="pa30_469">{{cite journal | last=Russell | first=Henry Norris | title=The New International Symbols for the Constellations | journal=Popular Astronomy | volume=30 | pages=469–71 | 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 by a polygon of 3 main and 7 western edgework forming sides (''illustrated in infobox''). In the [[equatorial coordinate system]], the [[right ascension]] coordinates of these borders lie between {{RA|07|55|19.7973}} and {{RA|09|22|35.0364}}, while the [[declination]] coordinates are between {{dec|33.1415138}} and {{dec|6.4700689}}.<ref name="boundary"/> Covering 506 square degrees or 0.921% of the sky, it ranks 31st of the 88 constellations in size. It can be seen at latitudes between +90° and -60° and is best visible at 9 p.m. during the month of March. Cancer borders the bright constellations of [[Leo (constellation)|Leo]], [[Gemini (constellation)|Gemini]] and [[Canis Minor]]. Under city skies, Cancer is invisible to the naked eye.