Vedāga Jyotia: An Earliest Full-fledged Treatise of Indian Astronomy

Vedāga Jyotia is an oldest hand book on Vedic astronomical observations in India. This small text, consists of a few pages of Sanskrit verses, has its historical importance in astronomy and mathematics because of the position of solstices and equinoxes recorded therein. This oldest astronomical treatise is a collection of seventy nine verses in two recensions. The first recensionknown as, Ārca- Jyotia, and consists of thirty six verses from Rigveda and the second recensionknown as, Yājua -Jyotia, which consists of forty three verses from Yajurveda. However, most of the verses are common in both recensions. This treatise ‘Vedāga Jyotia’ on mathematical astronomy was authored by ‘Rishi’ Lagadha probably in latter Vedic period. In Vedāga Jyotia, mainly the motions of the Moon and the Sun were summarized to perform the Vedic rituals and periodic sacrifices at particular times. The Vedāga Jyotia preserves the traditional knowledge of mathematical sciences, which was developed during Vedic period. The achievement in astronomy was based on mathematical calculations. The object of this paper is to bring out the mathematical rules used in Vedāga Jyotia for astronomical calculations, time period and place of observations, division of time and description of some the important studies of Vedāga Jyotia in chronological order.