= Equinox
{disambiguate=celestial coordinates}
{wiki}
= Reference equinox
{synonym}
The <reference equinox> is the direction conventionally used as the origin of <right ascension>: the northward intersection of the <Sun>'s annual path with the reference <celestial equator>. Its mean or true convention and reference date specify which direction is intended. Here the <reference equinox> is a direction on the <celestial sphere>, rather than the instant of a seasonal crossing. https://aa.usno.navy.mil/faq/asa_glossary[US Naval Observatory: Equinox and mean versus true reference directions]{ref}.
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