Editing Ophiuchus (section)

==Zodiac==
{{main|Ophiuchus (astrology)}}

Ophiuchus is one of the 13 constellations that cross the [[ecliptic]].<ref>Shapiro, Lee T. [http://spaceplace.nasa.gov/starfinder3/ "Constellations in the zodiac"], in ''The Space Place'' (NASA, last updated 22 July 2011)</ref> It has sometimes been suggested as the "13th sign of the [[zodiac]]". However, this confuses [[zodiac sign|zodiac or astrological signs]] with [[constellations]].<ref>{{cite web|url=https://earthsky.org/sky-archive/ophiuchus-highest-on-august-evenings-2|title=Ophiuchus, 13th constellation of zodiac|work= Earth Sky | access-date = 2019-07-19}}</ref> The signs of the zodiac are a 12-fold division of the ecliptic, so that each sign spans 30° of celestial longitude, approximately the distance the Sun travels in a month, and (in the Western tradition) are aligned with the seasons so that the [[March equinox]] always falls on the boundary between Pisces and Aries.<ref>{{Cite web|last=Gleason|first=Edward|title=Why is the vernal equinox called the "First Point of Aries" when the Sun is actually in Pisces on this date? {{!}} Planetarium|url=https://usm.maine.edu/planet/why-vernal-equinox-called-first-point-aries-when-sun-actually-pisces-date|access-date=2022-03-25|website=University of Southern Maine}}</ref><ref>{{Cite web|last=Campbell|first=Tina|date=2020-07-15|title=Has your star sign changed following the discovery of a 'new' Zodiac sign?|url=https://metro.co.uk/2020/07/15/what-new-zodiac-sign-ophichius-mean-what-dates-cover-12990848/|access-date=2021-04-29|website=Metro|language=en}}</ref> Constellations, on the other hand, are unequal in size and are based on the positions of the stars. The [[Zodiacal constellation#Constellations|constellations of the zodiac]] have only a loose association with the signs of the zodiac, and do not in general coincide with them.<ref>{{cite web |url=http://astrologyclub.org/ophiuchus-13th-zodiac-sign-no/ |title=Ophiuchus – a 13th&nbsp;Zodiac Sign? No! |work=Astrology Club |access-date=2016-10-18 |date=2 March 2016}}</ref> In Western astrology the constellation of Aquarius, for example, largely corresponds to the sign of Pisces. Similarly, the constellation of Ophiuchus occupies most (29&nbsp;November – 18&nbsp;December<ref>{{cite web |url=http://earthsky.org/constellations/born-between-november-29-and-december-18-heres-your-constellation |title=Born under the sign of Ophiuchus? |date=16 August 2021 |publisher=EarthSky.org}}</ref>) of the sign of Sagittarius (23&nbsp;November – 21&nbsp;December). The differences are due to the fact that the time of year that the Sun passes through a particular zodiac constellation's position has slowly changed (because of the [[Axial precession|precession of the Earth's rotational axis]]) over the centuries from when the [[Babylonians]] originally developed the zodiac.<ref>{{cite journal |last=Aitken |first=Robert G. |title=Edmund Halley and Stellar Proper Motions |journal=Astronomical Society of the Pacific Leaflets |date=October 1942 |volume=4 |issue=164 |pages=103 |bibcode=1942ASPL....4..103A}}</ref><ref>{{cite web |last=Redd |first=Nola Taylor |title=Constellations: The Zodiac Constellation Names |url=http://www.space.com/15722-constellations.html |publisher=space.com |access-date=3 August 2012}}</ref>