The Nakshatras (Lunar Mansions)
. . .practically all fundamental concepts and methods of ancient astronomy, for the better or the worse, can be traced back either to Babylonian or to Greek astronomy. In other words, none of the other civilizations of antiquity, which have otherwise contributed so much to the material and artistic culture of the world, have ever reached an independent level of scientific thought. Only into astrology were incorporated two remnants of pre-scientific astronomical lore from other than Mesopotamian or Greek background: the 36 Egyptian "Decans" and the 28 Indian "Lunar Mansions" (nakshatras).1
Three divisions of the twelve zodiacal constellations originated independently of one another: the sidereal zodiac (12 equal signs each 30° in length) in Babylon, the 36 decans (10° divisions) in Egypt, and the 28 nakshatras in India. In the course of time, both the decans and the nakshatras were assimilated into the sidereal zodiac.
After the introduction of the zodiac from Mesopotamia into Egypt not long after the founding of Alexandria in 332 BC, the 36 Egyptian decans became assimilated into the zodiac, three decans to a zodiacal sign, each decan corresponding to 10° in a given sign. The Egyptian decans are of considerable antiquity, first appearing on coffin lids around 2150 BC. Similarly, the 28 Indian lunar mansions have a history dating back to around the beginning of the last millennium BC. The 28 nakshatras, as the Indian lunar mansions are called, comprise a lunar zodiac marking the passage of the Moon around the night sky. The nakshatras are alluded to in the Vedas.2
Seeking favour of the twenty-eight-fold wondrous ones, shining in the sky together, ever-moving, hasting in the creation, I worship with songs the days, the firmament.3
As in the Egyptian decan lists, the earliest nakshatra lists associate each lunar mansion with a presiding deity (seeTable below) - for example, the deity of Krittika, the first nakshatra in the Vedic lists, is Agni. The Pleiades are the stellar determinants of Krittika. This fact alone, that the Pleiades are associated with the beginning of the lunar zodiac (of 28 nakshatras),4 suffices to distinguish it from the Babylonian sidereal zodiac, whose premier sign is marked by the stars of Aries. Interestingly, the Babylonian astronomers did draw an association between the Pleiades and the Moon, ascribing the "exaltation" of the Moon to this star cluster.
An exact definition of the lunar zodiac of nakshatras in relation to the Babylonian sidereal zodiac is not known, and therefore the above Figure represents a schematic relationship of the 28 nakshatras in connection with the twelve signs of the Babylonian sidereal zodiac. In the Vedas the 28 nakshatras are not defined precisely in relation to the fixed stars, nor are the nakshatras necessarily of equal length. In order that the stellar determinants of each nakshatra may be readily found, however, the 28 nakshatras are assumed to be of equal length, each 12°51'26" long, with the 1st nakshatra, Krittika, beginning at 0° Taurus in the Babylonian zodiac. The zero point of the lunar zodiac is here defined to coincide with 0° Taurus not only for the sake of convenience but also because this choice yields a close agreement with the known stellar determinants of nakshatras (see Table below). Using the above Figure in conjunction with the reconstructed Babylonian star catalogue (Appendix 1 in Robert Powell's History of the Zodiac), the fixed stars belonging to each nakshatra are easily found.
The Moon passes through the zodiac of 28 nakshatras in one (sidereal) month of approximately 27 and one-third days, spending approximately 24 hours in each nakshatra. In the course of this "nakshatra month" the Moon becomes full in a particular nakshatra. Generally the lunar synodic months in ancient Hindu culture were named after the nakshatra (or its neighbour) in which the Moon became full - for example, according to tradition Gautama Buddha was born at the full Moon in the (lunar) month of Vaisakka, that is, when the full Moon stood in the 14th nakshatra, Visakha, whose stellar determinants are the "balance pans" Alpha and Beta Librae.
The use of lunar asterisms in astronomy and astrology is evident not only in India but also in China, Persia, Greece, and Egypt. They were named manzils, by Islamic astronomers. Arabic verses in which weather lore is related to the full Moon in a given manzil reflect a similar usage of the manzils by the Muslims to that of the nakshatras by the Hindus, although in Indian culture it was especially the ceremonial aspect of the nakshatras, with each nakshatra being sacred to some deity, that was important (see Table).
The 28 Nakshatras and Their Deities
|Ecliptic Longitude||Nakshatra||Vedic Deity||Zodiac Sign Abbreviations|
|1||00°00' TA-12°51' TA||Krittika||Agni||Aries AR|
|2||12°51' TA-25°43' TA||Rohini||Prajapati||(Ram)|
|3||25°43' TA-08°34'GE||Mrigasiras||Soma||Taurus TA|
|4||08°34' GE-21°26' GE||Ardra||Rudra||(Bull)|
|5||21°26' GE-04°17' CN||Punarvasu||Aditi||Gemini GE|
|6||04°17' CN-17°09' CN||Pushya||Brhaspati||(Twins)|
|7||17°09' CN-00°00' LE||Aslesha||Sarpah (the Serpents)||Cancer CN|
|8||00°00' LE-12°51' LE||Magha||Pitarah (the Fathers)||(Crab)|
|9||12°51' LE-25°43' LE||Purvaphalguni||Aryaman||Leo LE|
|10||25°43' LE-08°34' VI||Uttaraphalguni||Bhaga||(Lion)|
|11||08°34' VI-21°26' VI||Hasta||Savitar||Virgo VI|
|12||21°26' VI-04°17' LI||Chitra||Tvastar*||(Virgin)|
|13||04°17' LI-17°09' LI||Svati||Vayu||Libra LI|
|14||17°09' LI-00°00' SC||Visakha||Indra and Agni||(Scales)|
|15||00°00' SC-12°51' SC||Anuradha||Mitra||Scorpio SC|
|16||12°51' SC-25°43' SC||Jyestha||Indra||(Scorpion)|
|17||25°43' SC-08°34' SG||Mula||Nirrti*||Sagittarius SG|
|18||08°34' SG-21°26' SG||Purvashadha||Apah (the Waters)||(Archer)|
|19||21°26' SG-04°17' CP||Uttarashadha||Vishve-Devah||Capricorn CP|
|20||04°17' CP-17°09' CP||Abhijit||Brahma||(Goat)|
|21||17°09' CP-00°00' AQ||Sravana||Vishnu||Aquarius AQ|
|22||00°00'AQ-12°51'AQ||Dhanistha||Vasavah (the Vasus)||(Water-Bearer)|
|23||12°51' AQ-25°43' AQ||Satabhisaj||Varuna*||Pisces PI|
|24||25°43' AQ-08°34' PI||Purvabhadrapada||Aja Ekapad||(Fishes)|
|25||08°34' PI-21°26' PI||Uttarabhadrapada||Ahi Budhniya|
|26||21°26' PI-04°17' AR||Revati||Pusan|
|27||04°17' AR-17°09' AR||Asvini||Asvinau (the 2 Asvins)|
|28||17°09' AR-00°00' TA||Bharani||Yama|
See the above Figure for the schematic definition of the lunar nakshatras in relation to the Babylonian zodiac as indicated in this Table. It is assumed that the nakshatras are of equal length, each 12°51'26" long, with the first nakshatra, Krittika, beginning at 0° Taurus in the Babylonian sidereal zodiac. This definition conforms well with the stellar determinants of the nakshatras, and with the stellar determinants of the corresponding manzils. The Vedic deities are those given by P.V. Kane, History of Dharmasāstra (1962), volume V, 1, pp. 501-504, except those marked with an asterisk (*), which are duplicates in Kane's list and are therefore replaced by the deities listed by Paul-Emile Dumont in his article "The Istis to the Nakshatras," in Proceedings of the American Philosophical Society 98 (1954), p. 205. Otherwise the two lists are identical, with the exception of certain of Dumont's renderings (given in parentheses).
1 Otto Neugebauer, History of Ancient Mathematical Astronomy, volume I, p. 6.
2 There is some controversy over the dating of the Vedas, but it is possible that their date of composition lies anterior to 800 BC.
3 Arthava-veda Samhita XIX.7.i (translated by Whitney, p. 906).
4 After the introduction of the zodiac into India, probably in the second century AD, the nakshatras became redefined. Asvini, with marking stars Beta and Gamma Arietis, became the premier nakshatra, and one of the nakshatras became discarded, leaving 27 nakshatras in the later Indian astronomy from around the second century AD onwards.