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	It has been argued that the Vedanga Jyotisa could date to ca. 1370 BCE.<ref>Kak 2000:87</ref>		It has been argued that the Vedanga Jyotisa could date to ca. 1370 BCE.<ref>Kak 2000:87</ref>

			=== Mahabharata ===

			Aryabhata dated the Mahabharata war to 3100 BCE, and Varahamihira to 2400 BCE.<ref>Cf. Subhash Kak, The astronomy of the age of geometric altars, Quarterly Journal of the Royal Astronomical Society 36, 1995</ref>

	=== Dhanisthta nakshatra ===		=== Dhanisthta nakshatra ===
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	The ], the ], the ], the ] and the ] show such a constellation in the Krittika<ref> (Frawley 1991)</ref>.		The ], the ], the ], the ] and the ] show such a constellation in the Krittika<ref> (Frawley 1991)</ref>.

			== Terminology ==

			*mahavrata: ]
			*visuva: ]
			*visuvant: ]

	==Notes==		==Notes==

Revision as of 21:48, 17 October 2006

Hindu Astronomy is one of the ancient astronomical systems of the world.

The astronomy and the astrology of India is based upon sidereal calculations. The sidereal astronomy is based upon the stars and the sidereal period is the time that it takes the object to make one full orbit around the Sun, relative to the stars. This is considered to be an object's true orbital period.

In discussions of Hindu astronomy, it should be cleanly disambiguated whether actual ancient astronomical (or astrological, a distinction that did not exist in pre-modern India any more than in pre-modern Europe) treatises are discussed, or if archaeoastronomical claims are distilled from alleged codes or statements taken from the Vedas.

Hindu astronomy and astrology

Main article: Hindu astrology

In Hindu Astronomy, the vernal equinox (the First Point of Aries) is often calculated at 23° from 0° Aries (1950 CE), i.e. about 7° Pisces . The constellation that marks this vernal equinox is the Uttarabhadra.

In the time of the Puranas, the vernal equinox was marked by the Ashwini constellation (beginning of Aries), which gives a date of about 300-500 CE. The Vishnu Purana (2.8.63) states that the equinoxes occur when the Sun enters Aries] and Libra, and that when the sun enters Capricorn, his northern course (from winter to summer solstice) commences, and the southern course when he enters Cancer.

In the Suryasiddhanta, the rate of precession is set at 54" (it actually is 50.3"), which is much more accurate than the number calculated by the Greeks .

The Hindus use a system of 27 or 28 Nakshatras (lunar constellations) to calculate a month. Each month can be divided into 30 lunar tithis (days). There are usually 360 or 366 days in a year.

Hindu astronomical treatises:

Suryasiddhanta

Hindu astronomy and Indian chronology

Rigveda

There are claims, like that of Subhash Kak of an Astronomical Code of the Rgveda dating the Rigveda to the 4th millennium; Kak's results have been criticized by Plofker as having "no statistical significance whatsoever", even if overlooking their being based on the structure of the Iron Age shakha (recension) of Shakala rather than the content of the actual Rigvedic texts.

Vedanga Jyotisa

It has been argued that the Vedanga Jyotisa could date to ca. 1370 BCE.

Mahabharata

Aryabhata dated the Mahabharata war to 3100 BCE, and Varahamihira to 2400 BCE.

Dhanisthta nakshatra

The Hindu astronomer Varahamihira, Garga (quoted by Somakara), the Mahabharata and the Vedanga Jyothish refer to the nakshatra Dhanishta (Shravishta) and thus to an ancient calendar that would have been used in 1280 BCE . The Kaushitaki Brahmana and possibly the Atharvaveda refer to a similar calendar . The Atharvaveda, the Tandya Mahabrahmana and Laughakshi (quoted by Somakara) may show knowledge of an earlier calendar, but still in the Magha constellation .

Krittika constellation

Still earlier Hindu calendars begin with the Krittikas, thus suggesting that the vernal equinox was in the Krittika constellation. There are additionally references to the summer solstice in the Magha constellation. This could indicate a date around 2000 BCE. The Shatapatha Brahmana has the Krttikas (the Pleiades) "do not swerve from the east". This would have been the case with precision during the 30th and 29th centuries BCE and was true also about 2000 BCE, but was still true to within 8-13 degrees (viz., East by north) around 800 BC, the assumed date of the text's composition.

The Atharvaveda, the Taittiriya Brahmana, the Shatapatha Brahmana, the Maitrayaniya Upanishad and the Vishnu Purana show such a constellation in the Krittika.

Terminology

mahavrata: winter solstice
visuva: spring equinox
visuvant: summer solstice

Notes

(Frawley 1991:148)
(Frawley 1991:148)
S. Kak, The Astronomical Code of the Rgveda. New Delhi: Aditya Prakashan 1994.
Plofker, K. Review of Kak (1994), Centaurus 38 (1996), 362-364; see also Witzel EJVS Vol. 7 (2001) issue 3 (May)
Kak 2000:87
Cf. Subhash Kak, The astronomy of the age of geometric altars, Quarterly Journal of the Royal Astronomical Society 36, 1995
(see Frawley 1991: 152 ff.)
(Frawley 1991)
(Frawley 1991)
Kak, Subhash: Archaeoastronomy and Literature, Current Science, vol. 73, no.7, 1997
ŚBM 2.1.2.1: kṛttikāsv agnī ādadhīta ... etā ha vai prācyai diśo na cyavante "One should found one's fires under the Krttikas ... These do not swerve from the eastern direction"; the emphasis on "due east" is due to the 14th c. commentary by Sayana.
Kak, Subhash: Archaeoastronomy and Literature, Current Science, vol. 73, no.7, 1997
Texts of the Brahmana period do only distinguish intermediate directions, viz. eighths of the compass, and the rising of the Pleiades fell into the Eastern eighth until well after the Vedic period. See also Michael Witzel, The Pleiades and the Bears viewed from inside the Vedic texts, EVJS Vol. 5 (1999), issue 2 (December) (Witzel speculates that the reference may be based on centuries old priestly traditions of times when the Pleiades were even closer to due East) and Witzel EJVS Vol. 7 (2001) issue 3 (May)
(Frawley 1991)