This lecture series provides an introduction to the observational foundations of ancient Indian astronomy. Delivered as part of the Indian Knowledge Systems (IKS) curriculum at Jain (Deemed-to-be) University, the materials outline the foundational methods used by ancient observers to track celestial motion, establish calendars, and record long-term astronomical shifts.

Presentation Materials

Core Topics Covered

  1. Rhythms of Celestial Objects: Systematic tracking of the Sun and Moon, noting daily changes in rising/setting positions.
  2. Calendar Systems: Structural outline of Luni-Solar calendars (Panchanga, Tithi, Masa).
  3. Nakṣatras as Sky Coordinate Divisions: Space/time mapping of the ecliptic.
  4. Precession of the Equinoxes: Understanding the slow westward drift of solstitial and equinoctial points and its application in dating ancient texts.

Seasonal Nakṣatra Drift

Axial precession causes the nakṣatra associated with a given season to drift backwards over time at a rate of approximately 1° every 72 years (or one full nakṣatra span of 13°20’ in roughly 960 years). This astronomical clock is one of the key tools for chronological dating of ancient literature like the Vedas and Puranas.

Seasonal Nakshatra Drift Demo