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History of star names

Every society in human history has had its own vision and definition of skies. The precision of Egyptian,(Chaldean/Akkadian) Messapotamian, Mayan, Stonehenge, Chinese culture are known to us, and certainly there must have been many others unknown to documented history. The stars in the skies were identified and named as single stars or groups and their relation to sun movement has been observed (Ref 6,7,8,9).

Chinese have had a long tradition of astronomical observations. They appear to have used, Sun, Moon and Jupiter as pointers which included zodiac division in to 28 segments as early as 1200 BC. The 28 segmental division is somewhat similar to vedic system. The starting position of the 28 zodiacs was in Libra (near Swati or Vishakha). That appears to rule out Chinese interaction with Vedic culture.

The concept of animal shaped zodiac representing 10-12 zodiacs per year is attributed to Chaldean and Akkadian cultures of Messapotamia. Egyptian Dendera Palnisphere, presently in France, which has been dated to about 1800 BC shows the twelve zodiacs (Ref 4). The earliest traceable documentation from European sources is by Ptolemy in 130 AD, who lived in Alexandria in current Egypt. He compiled data from many centuries of European knowledge before him and he used Hipparchus's astronomical observations (nearly 300 year older than Ptolemy) for many of his observations. The observation of Earth's Precession is attributed to Ptolemy and Hipparchus, and is a major astronomical observational finding. Ptolemy’s works comes down to modern days via Arab astronomers who called his work `Al magist’. In this Ptolemy, refers to 48 constellations in the skies. He used the Egyptian year and month names, which were well advanced and similar to Julian system. Interaction of middle eastern/European astronomical knowledge with Bharateeya knowledge clearly must have happened, much before Ptolemy when many Greeks were in Bhaarat. Ptolemy's zodiac boundaries are different from present zodiac boundaries of same name. The Arab astronomers used Ptolemy's data base and made a thorough study of the skies after Ptolemy and many individual stars were named by them in post Ptolemy centuries. These names have been widely accepted and used.

During many centuries after Ptolemy's time, number of changes have occurred in constellation definitions and boundaries. In 17th century, Bayer systematically named stars using three parameters, first to give star a serial number in its constellation, and second to assign a Greek alphabet representative of the brightness and third to refer to constellation where star is. Therefore a should always be the brightest star of the constellation followed by b, etc. Flamsteed numbers are another catalog of stars from same era. The presently accepted 88 Zodiac definition was frozen in 1932 by International Astronomical Union and stars are named by Bayer's system. This came about because of the meriad constellation names and boundaries that were being floated at that time.

Since the profound beginnings of modern astronomy by Kepler, Galileo, Newton and their astonishing advances in recent times by Hubble and others, extensive and detailed catalogs of all bodies in skies have been made. Optical and other electromagnetic wavelength telescopes have been used to study all objects in the skies. The modern astronomers have a very precise understanding of major and minor planetary motion, binary stars, Messier objects, Comets, and even man made objects in sky. Modern astronomical science has catalogs all the visible stars. The identification currently extensively used in modern astronomy is the HD number standing for Henry Draper Classifications, and SAO number standing for Smithsonian Astronomical Observatory catalog number. There are star catalogs from Germany, France, and Britain.

Most of the European style analysis of astronomical references in veda's (starting from German and British writers of 19 and early 20th century) have always suggested that the vedic text astronomical observations were generally primitive and any non-primitive elements were some how derived from Messapotamian/Akkadian/Chaldean origins. These analyses trivialize any significant original observations in the Veda's. This bias has been brought out be David Frawley succinctly in his work (ref-8).

Star Brightness/rules used for identifying Vedic star equivalence

Star brightness has been numerically expressed since Hipparchus in 150 BC. The scale presently used to measure brightness of objects is an inverse geometrical scale with brightness of sun at -26. With such a bright object, flooding atmosphere, other objects in sky are only visible to normal human eyes during night when sun is not visible. Full moon has a brightness of -12. Venus at its brightest has a brightness of -3. A change of brightness by 2.56 refers to a change of brightness by factor of two. The brightest star is Sirius, which has a brightness of -1.5. On a clear dark night (without moon), the dullest object that can be seen by healthy human eye is considered to be +6.

The following principles and assumptions can perhaps be used as the basis for establishing identity of Bharateeya Nakshatras in this article.

*Nakshatra named by people at Vedic time, must have been visible to naked eye and hence must be brighter than +5, based on brightness definitions.

*Moon is said to visit the Nakshatra or star mansions. Moon traverse plane is inclined to sun motion plane and hence over a period of time, the moon trajectories form a band. Let us call it as the moon traverse band. It is typically 5 degrees around ecliptic. Hence for any star or group of stars to qualify as a Nakshatra, it must be within the moon traverse band or outside not exceeding a few moon diameters. One Moon diameter is about 0.6 degree as seen from earth.

* The Nakshatras should be about 13.33 degrees apart or to 1/27 of 360.

* It is also necessary that they belong to the Raashi's or twelve Zodiacs. There are 88 officially identified zodiacs in the sky, moon traverse band passes only through 12. It should be noted that the Raashi or zodiac boundaries may vary from past definitions of 2400 years ago when possibly the Zodiac concepts were amalgamated in to Jyotishya.

*In Bharat, the traditional Panchangas/almanacs provide chandramana details including the beginning and end of visit of moon to 27 Nakshatras time to within few minutes of accuracy for every day of the year. Such almanacs are used even today for religious purposes. This data has to correlate with our identification in that moon must be near the star.

Implicit in these rules is the assumption that Jyotishya Shaastra experts of circa 400 BC carried forward the knowledge and identity of the Nakshatras correctly from vedic period accurately in correlating nakshatra's to Raashi's at that time. It is this interrelation of Nakshatras and Raashi's that permit us to identify what the vedic time names of stars were. The effect of natural motion of stars is assumed to be insignificant, but accounting for precession or Ayanamsha is necessary.

An astronomical computer software, LOADSTAR PRO GS has been used to identify the traditional Bharateeya Nakshatras and their equivalents based on the rules and assumptions declared above.



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