Lunar node
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The lunar nodes are the orbital nodes of the Moon, that is, the points where the orbit of the Moon crosses the ecliptic (which is the apparent path of the Sun across the heavens against the background stars). The north or ascending node is where the moon crosses to the north of the ecliptic. The south or descending node is where it crosses to the south.
Eclipses occur only near to the lunar nodes: Solar eclipses occur when the passage of the Moon through a node coincides with the new moon; lunar eclipses occur when it coincides with the full moon. Moon's distance to the nodes will be less than about 1,5° <ref> André Danjon. Astronomie Générale. 2nd Edition, Paris, 1980. </ref>.
The lunar nodes precess rather quickly around the ecliptic, completing a revolution (called a draconitic or nodical period, the period of nutation) in 6793.5 d or 18.5996 a. (that is not the Saros-period)
The symbol of the ascending node is Image:Northnode-symbol.png, the astronomical and astrological symbol for the Dragon's head (Caput draconis). The symbol of the descending node is Image:Southnode-symbol.png, the astronomical and astrological symbol for the Dragon's tail (Cauda draconis).
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Symbols
The Lunar node symbols look like horseshoes. The horseshoe is open on the bottom for the north node and open on the top for the south node. The same symbol is also used to represent the constellation Draco.
Names
The North Lunar Node is called by different names in different areas of the world. Since it is the point at which the interception is made while the moon is ascending from the south to the north, it is also called the ascending node. In ancient texts, the north node is referred to as the dragon's head (Caput Draconis). The south node is also known as the descending node or the dragon's tail (Cauda Draconis). In Hindu astrology (or Jyotish), the north node is called Rahu and the south node is called Ketu.
Astrological significance
The lunar nodes are of major astrological significance in Vedic astrology, and are considered to a limited degree in Western astrology. Usually only the north node is marked in horoscopes, as the south node is by definition always located at the opposite point in the astrological chart.
Their significance can vary widely between approaches. In general, the north node is viewed a point of opportunity for growth and development and self help, while the south node is thought to represent karmic repression or tendencies that restrict growth. The north node carries the positive and ultra-beneficial tone of Jupiter, while the south node expresses the restrictions and obstacles of Saturn. Another view is that the north node represents positive objectives and the south node denotes the easy way out with little opportunity for growth. The two nodes together are most commonly referred to simply as the nodal axis, the lunar nodes, or the moon's nodes.
See also
References
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External links
- Sun and Moon Polar Applet, showing moonrise/moonset azimuths
- Astronomy Answers: What are the standstills of the Moon?de:Mondknoten