Bill McBride, a LexiLine list member, commenting on my posting at 59 LexiLine Newsletter 2005 The Cult of Horus Nr. 4, where I write "Thuban may have been viewed as the pole star ca. 2800-2600 B.C. by the ancients, but we have no evidence of this in available sources....", has written to me as follows:
>Thuban was the north star in Draco during the building
>of the Great pyramid in Giza.
>This can be proven by doing a precession astronomy
>program like Starry Night Pro.
This is a very interesting observation, with an even more interesting answer.
Thank you, Bill, for raising this question.
There is of course no dispute with the fact that the fairly weak visible star Thuban neared the north celestial pole in the 3rd millennium, coming closest to within 10' of that pole ca. 2750 BC, according to Richard Hinckley Allen's Star Names (p. 206).
However, this does not mean 1) that Thuban was at that time assigned to a constellation which is the comparable of Draco today, or 2) that the ancients actually USED Thuban to mark the north celestial pole.
Thuban is simply not bright enough as a star to be used practically for this purpose and that is why the ancients used the nearby Kochab and Pherkad , which are much more visible.
Bill is surely referring to the work of Robert Bauval on the four main shafts of the Great Pyramid of Giza. Bauval claims that these four shafts point to the stars Thuban, Al Nitak, Sirius and Kochab.
But the actual slope of the shafts does not support this contention. As written by Frank Dörnenburg (Doernenburg) at The Orion-Pyramids: Technical Examinations: The Shafts, the following "corrected" years (i.e. corrected from Bauval's figures) represent in fact the years when the actually measured slope of the shafts would have pointed to the selected star (or near it). This is later than what Bauval claims but supports well our own solar eclipse theory and our dates for the pyramids which are more correctly later than anyone else has thus far suggested. See LexiLine.
Dörnenburg writes that Rudolf Gantenbrink determined the slopes of the shafts and that Bauval has not stuck to these consistently and has used some date correction schemes such as "epochs" which are questionable.
The Gantenbrink data applied to the stars results in this data: (columns may skew on the internet)
Star.......Decl......Elev......Shaft......Error.....Nec. Decl....Corr. Year
Thuban.....88°01'....31°57'....32°36'....-39'.......87°20'.......-2326
Al Nitak..-14°49'....44°49'....45°.......-11'......-15°02'......-2496
Sirius....-20°42'....39°20'....39°36'....-16'......-20°26'......-2348
Kochab.....80°38'....39°20'....39°07'....+13'.......80°51'......-2385
Note that the error with respect to Al Nitak, Sirius and Kochab is about the same and that these could well have been sighted directly. The error with respect to Thuban, however, is disproportionately large, and it is possible that the Cheops pyramid was being used to locate the ACTUAL north celestial pole, which at the time of the building of the pyramids was not directly at Thuban - nor do we have any evidence that Thuban was ever used as the "pole star" in this connection. The Giza shaft simply does not point directly at Thuban.
Quite the contrary, what other reason is there to sight Kochab other than that THIS was the traditional pole star in ancient Egypt, and, as Kate Spence (apparently relying in part on Bauval's work) has written, a line through Kochab and Mizar at the time of the building of Cheops marked "true North" and would have aided the ancients in building the Cheops pyramid, which may in fact have been built because of precession as an instrument to determine or verify precession.
There is even the possibility that KOCHAB as a term is identical in origin with the Greek CHEOP-s, i.e. Cheop=Kochab. That Kochab was used as the pole star in distant antiquity is perhaps also substantiated by the fact that KAWKAB means simply "THE star" in Arabic (Arabic الكوكب al-kawkab and is basically the same word as the Hebrew term for "star" which is KOKAB.
Richard Hinckley Allen writes (p.450) that it was Ursa Minor that was called Doube (the "guiding one") by the Phoenicians and not Thuban, whereas, as Allen reports, "Jacob Bryant assigned it [Ursa Minor] to Egypt, or Phoenicia as Cahen ourah [Horus?], -- whatever that may be." Allen writes that "Kochab...perhaps was this star the Greek astronomers called POLOS [pole star]. (p. 450)
We thus have many sources that verify Kochab being used as an ancient polestar and no such sources for Thuban.