Ayana - Its astronomical and astrological Importance

A very important phenomenon in Muhurta is that of the two Ayanas, Uttarayana and

Dakshinayana. Ayana in Jyotish Veda is known as a period of time during a year when Surya (the Sun) moves towards a certain direction passing through certain Rashi.

Ayana literally means “course” as well as being the name of the solstices.

Uttara means upper and superior as well as referring to the northern direction.  During its northward movement, From the moment of touching the tropic of Makara (Capricorn) (so-called tropical Makara Sankranti), Surya moves northward till it reaches the tropic of Karkata (Cancer). During this period Surya passes through the signs of Makara (Capricorn), Kumbha (Aquarius), Meena (Pisces), Mesha (Aries), Vrshabha (Taurus) and Mithuna (Gemini) covering six months. Which is also called as Uttara Ayana.

Uttarayana begins at zero degrees tropical Capricorn and lasts for six Saura months, until the Sun reaches zero degrees tropical Cancer. This period in Vedic tradition is considered to be auspicious, as it's known as "Deva Day", and all events taking place at this time, are under supervision of Devas (Gods). So it is believed that this period is auspicious for holding such big events as marriage, moving into a new house and so on. In Mythology it is quite evident that Bhishma Pitamaha laid down on a bed of arrows waiting for Uttarayana to leave his mortal body.

Dakshina means compliant and able, as well as referring to the southern direction. The period during which the Sun moves south is known, therefore, as Dakshinayana or Pitrayana.

 From the moment of touching the tropic of Karkata (Cancer) (so-called tropical Karkata Sankranti), Surya (the Sun) begins its southward journey, known as Dakshinayana, till it reaches the tropic of Makara (Capricorn). During its southward movement, Surya passes through the signs of Karkata (Cancer), Simha (Leo), Kanya (Virgo), Tula (Libra), Vrshchika (Scorpio) and Dhanu (Sagittarius).

Dakshinayana begins at zero degrees tropical Cancer and also lasts for six Saura months, until the Sun reaches zero degrees tropical Capricorn.

This period in Vedic tradition is inauspicious, and is known as "a night of Devas" when all events taking place at this period of time are under the supervision of the Asuras (demons).

As the name infers, Uttarayana is considered more auspicious than is Dakshinayana, and certain events are best done during Uttarayana. Reading & Listening Srimad Maha Bhagvatham is extremly beneficial during Dakshinayan

It is extremely important that tropical zodiac (not the sidereal one) is used for the calculation of Ayana. It is a fundamental principle that is supported by many classical sources. Many astrologers consider the Ayanas based on the sidereal zodiac, which is inaccurate and not supported by the Surya Siddhanta, nor is it supported by Varahamihira’s Brihat Samhita, which states in chapter 3,slokas 1 & 2:

“There was indeed a time when Dakshinayana began from the middle of Aslesha

(23º 20’ sidereal Cancer) and Uttarayana from the commencement of

Dhanishtha (23º 20’ sidereal Capricorn). For, it has been stated so in ancient

works.

At present Dakshinayana starts from the beginning of Cancer and the other from

the initial point of Capricorn. This actual fact, which goes against the old

statement, can be verified by direct observation.”

1. Drika Siddhanta:

Dakshinayana starts when sayana sun enters cancers, and uttaraayana starts when sayana surya enters Capricorn. We need to use sayana surya in order to observe surya’s ayana gati.

2. Drika Siddhanta and Nirayana System

Dakshinaaya starts when nirayana surya enters cancers, and uttaraayana starts when nirayana surya enters Capricorn. Actual Ayanagati may not be observed exactly using this method.

Among these two system ,Which one to use is the personal choice. However sankranti decision is always done using 2 method. It’s just Ayana gati and Ritu they donot follow ayanamsha. Sun’s Ayana gati is always tropical. Ritus always follow tropical sun, not nirayana sun.