1.2 The Day Sky

The Sun ruling the daytime, divides the day into twelve parts calling each a ‘rāśi’. Each rāśi measures 30° (=360° ÷ 12) and the reckoning starts from the opposite (pakṣa means opposite or 180°), the mid-point of Chitrā nakṣatra. This is the zero-degree of the zodiac. The ayanāṁśa which fixes this zodiac relative to the stars is called ‘Chitrā-pakṣa ayanāṁśa’. If this ayanāṁśa is not used, the zodiac seems to rotate relative to the stars taking about 25,800 years to return to its original position. This is the precession of the zodiac, the parikrama (circumambulation) of the entire solar system around ‘Hari’ – the Viṣṇu nābhi. This other zodiac is called the tropical zodiac or sāyana-chakra (Viṣṇu Chakra) while the sidereal zodiac is called the nirayana-chakra (Nārāyaṇa chakra).

Why do we use the sidereal nirayana chakra instead of the tropical sāyana chakra?

The sāyana chakra gives us the seasons and changes in weather phenomena as the Sun transits between the tropics – hence the western name ‘tropical’. It follows the ayanāṁśa and does not bother about the nakṣatra (stars of the night sky). Typical of the Sun as these nakṣatra are invisible in the say time, it ignores all the nocturnal phenomena.

In jyotiṣa we give a high importance to the manas, the mind of all creatures signified by the Moon and these nakṣatra cannot be ignored altogether. Yet we nee to have a zodiac that obeys the Sun but accounts for these stars. The result is the sideral zodiac which accepts the Sun as one among the many stars, although it is the most important star. It is like a soli-lunar system which accounts for both the Sun and the Moon – the day and night. This is the basis of Horā Śāstra.

Mystery of the Birth Month
Pt. Ramesh Chandra Bhattacharyya

Vedic Astrology is the science of study of time and space and its effect on the entire life and activities of earth which revolves the two principle luminaries viz., the Sun and the Moon. This ancient study of vedic astrology known as “Jyotish”. When transliterated, it is known as the study of Jyoti meaning light which comes naturally from the Sun.  This ancient science of Jyotish comprises of three major branches viz, (i) Hora Shastra – the study of time.  The word “Hora” has been derived from two words – “Aho” meaning day and “Ratra” meaning night; (ii) Ganita Shastra – the study of mathematical part of astrology and astronomy; and (iii) Gola Shastra – the study of astronomy, which included observation and analysis of stellar effects and the effects of the motion of planets in the solar system.

The Sun Signs called āditya are carved by the joint transit of the Sun and Moon. They dance in the heavens and meet every 30 days. During this time the Sun travels 30°. The complete transit of the Sun around the sidereal zodiac of 360° brings forth twelve such conjunctions resulting in twelve soli-lunar signs called māsa (Vedic month).

However, to fix this in solar space, we divide the zodiac into twelve parts of 30° each resulting in the twelve vedic Sun signs or rāśi.

The solar ingress into any sign is called a saṅkrānti and there are twelve saṅkrānti in a year. Of these the one that occurs when the Sun enters Capricorn (Makara rāśi) is of paramount importance as the Sun is simultaneously transiting the Abhijit nakṣatra (intercalary nakṣatra in Uttara Āsāḍha) and Hari is going to awaken.