Celestial meridiator

Celestial meridiator

Celestial meridiator is a vertical imaginary line that goes over the celestial poles and crosses (perpendicular to) the celestial equator. There are two celestial meridiators on the celestial sphere: Equinox meridiator and Solstice meridiator.


The meridiators are usually named from the points at which the sun reaches the certain point in the sky during the year. There are two reference points in the sky where sun crosses: equinox and solstice. Equinox occurs when sun passes the equinox point—the intersection between equinox meridian, equator, and the ecliptic. Equinox is also called ecliptic virgin. Solstice occurs when sun passes the solstice point—the intersection between solstice meridiator and ecliptic. Solstice is also called ecliptic peak.

There are four meridians, identical to the number of seasons each year. The meridians are normally named after the meridian of the start of the season when sun passes through the meridian.

Another alternative names of meridians are from the four reference points each day. There are midnight, morn, noon, and eve. Naming meridians from the four reference points of the day is coming from the right ascension or celestial longitude measured in hours from the Spring Meridian or midnight meridian. Using 24 hour military clocks have identical hour numbers throughout the 24 hour day as it is using time as a right ascension for celestial astronomy. Time for celestial astronomy never uses 12 hour span between the equinox meridians like the 12 hour clocks.

Midnight Meridian and Noon Meridian are equinox meridians and even going to the new hemispheres when going left after passing these meridians on the celestial map. Midnight and noon are also the start of the AM and PM respectively on the 12-hour clocks at 12:00.

Solstice meridians are in the center of the hemispheres. There are two solstice meridians: Morn Meridian and Eve Meridian. Morn and eve are the reference points of time which is exactly in the middle of AM and PM respectively at 6:00.

Equinox meridiator

Equinox meridiator is a celestial meridiator that passes over equinoxes when intersect the equator and ecliptic. Equinox meridiator can be subdivided into two meridians: Spring Meridian (Midnight Meridian) and Autumn Meridian (Noon Meridian).

Spring Meridian/Midnight Meridian is a meridian that passes over the vernal equinox (0° celestial latitude) while passes over the equator. It passes through midnight virgin when intersects the equator. It has celestial longitude 0° or 0h. Autumn Meridian/Noon Meridian is a meridian that when passes through the equator, it passes over the autumnal equinox (0° celestial latitude). This meridian passes through noon virgin when intersects the equator. It has celestial longitude 180° or 12h.

olstice meridiator

Solstice meridiator is a celestial meridiator that passes through solstices when intersects the ecliptic at the ecliptic peaks. It is further divided into Summer Meridian (Morn Meridian) and Winter Meridian (Eve Meridian).

Summer Meridian/Morn Meridian is a meridian. When intersects the ecliptic, it forms summer solstice. Summer solstice has a celestial latitude +23.45°. When this meridian intersects the equator, it forms morn virgin. The Summer solstice and Summer Meridian has a celestial longitude 90° or 6h.

Winter Meridian/Eve Meridian is a meridian. At a celestial latitude of −23.45° and celestial longitude 270° or 18h, there is the winter solstice—when ecliptic intersects the Winter Meridian. It also has the virgin—eve virgin—when Winter Meridian/Eve Meridian intersects the equator.

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  • Autumn Meridian — is a part of the equinox meridiator that passes through First point of Libra and has celestial longitude 180° (±180°) (12h). There are alternative names: Noon Meridian, First point of Libra Meridian, Virgo Meridian, September Meridian, Fall… …   Wikipedia

  • Spring Meridian — is a part of the equinox meridiator that has the celestial longitude 0° (±0°) (0h). It is also called celestial Prime Meridian, First point of Aries Meridian, Pisces Meridian, March Meridian, Vernal Meridian, and Midnight Meridian because during… …   Wikipedia

  • Summer Meridian — is a part of the solstice meridiator at which the celestial longitude 90° (+90°) (6h). On the celestial map, Summer Meridian is located in the center of the right side (eastern hemisphere) as a vertical line that runs from north pole to south… …   Wikipedia

  • Winter Meridian — is a part of the solstice meridiator on the celestial sphere. This meridian is located on the center of the western hemisphere. It has celestial longitude 270° (−90°) (18h). On the celestial map, Winter Meridian is located in central left side as …   Wikipedia

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