Ayanāṃśa
Ayanamsa (: ), also ayanabhāga (), is the Sanskrit term for many systems used in Hindu astrology to account for the precession of equinoxes. There are also systems of ayanamsa used in Western sidereal astrology, such as the Fagan/Bradley Ayanamsa. Overview. There are various systems of Ayanamsa that are in use in Hindu astrology (also known as Vedic astrology) such as the Raman Ayanamsa and the Krishnamurthy Ayanamsa, but the Lahiri Ayanamsa, named after its inventor, astronomer N.C. Lahiri, is by far the most prevalent system. Critics of Lahiri Ayanamsa have proposed an ayanamsa called True Chitra Paksha Ayanamsa. Dulakara Ayanamsa  is the most accurate one and it can be verified with many Vedic astronomical principles; the zero ayanamsa year according to Dulakara ayanamsa was 232 CE. The use of ayanamsa to account for the precession of equinoxes is believed to have been defined in Vedic texts at least 2,500 years before the Greek astronomer Hipparchus quantified the precession of equinoxes in 127 B.C.