Ayanamsa
The ayanamsa is the gap between the Western (tropical) zodiac and the Vedic (sidereal) zodiac. Subtracting it from a planet’s tropical position gives its sidereal position. It is about 24° today and grows slowly.
Also known as: ayanamsha, ayanansh
The tropical zodiac starts from the spring equinox point, which slides slowly backwards against the stars because of a wobble in the Earth’s axis called precession. The sidereal zodiac stays fixed to the stars. The gap between them grows by about 50 arc-seconds a year, or one degree in roughly 72 years.
Most Indian astrologers use the Lahiri (Chitrapaksha) ayanamsa, which places the star Spica (Chitra) at 0° Libra. India’s Calendar Reform Committee recommended it in the 1950s, and it is used for the official Indian ephemeris and throughout your Kundli. Its value was about 24°13′ during 2026.
Other ayanamsas exist, such as Raman and Krishnamurti (KP), and they differ from Lahiri by anything from a few arc-minutes to about one and a half degrees. That rarely matters, but it can move a planet or ascendant sitting right at the edge of a sign or nakshatra.