Vedanga Jyotisha

The Vedāṅga Jyotiṣa, or Jyotiṣavedāṅga (Devanagari वेदाङ्ग ज्योतिष) is one of earliest known Indian texts on astronomy and astrology (Jyotisha). The extant text is dated to the final centuries BCE, but it may be based on a tradition reaching back to about 700-600 BCE.

The text is foundational to Jyotisha, one of the six Vedanga disciplines. It was composed by Lagadha.

The dating of the Vedanga Jyotisha is relevant for the dating of the Vedic texts. The Vedanga Jyotisha describes the winter solstice for the period of ca. 1400 BCE. This description has been used to date the Vedanga Jyotisha. According to Michael Witzel, the question is "whether the description as given in the jyotiSa is also the date of the text in which it is transmitted." T. K. S. Sastry and R. Kochhar suppose that the Vedanga Jyotisha was written in the period that it describes, and therefore propose an early date, between 1370 and 1150 BCE.David Pingree dates the described solstice as about 1180 BCE, but notes that the relevance of this computation to the date of the Vedanga Jyotisha "is not evident." The estimation of 1400-1200 BCE has been followed by others, with Subbarayappa adding that the extant form can be possibly from 700-600 BCE.

Other authors propose a later composition. Santanu Chakraverti writes that it has been composed after 700 BCE, while Michael Witzel dates it to the last centuries BCE, based on the style of composing. According to Chakraverti, it's description of the winter solstice is correct for ca. 1400 BCE, but not for the time of its composition after 700 BCE. This may be due to the incorporation of late Harappan astronomical knowledge into the Vedic fold, an idea which is also proposed by Subbarayappa. Michael Witzel notes:

[O]nly if one is convinced that lagaDha intended the solstice to be exactly at alpha Delphini of dhaniSThA, one can date his observations back to the late second millennium. Since that cannot be shown beyond doubt, since the composition of the text is in Late Epic language, and since its contents have clear resemblances to Babylonian works, the text must belong to a late period, to the last centuries BCE.

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