162 North Star as the First Star of the Catalogue Almagest

According to Scaliger's chronology, the Almagest was compiled in the 2nd century A.D. or even a little earlier than the 2nd century. It is possible to verify that since the last two and half thousand years the closest star constellation to the north galactic pole was Ursa Minor. Then, we can also compute which of the stars in the Ursa Minor constellation was the closest to the north pole in the beginning of the Christian era about two thousand years ago, that means at the time traditionally associated with the creation of the Almagest. It turns out, that it was Beta Ursae Minoris — the star that is listed in the Almagest as a star of the second magnitude, while the North Star (Alpha Ursae Minoris or Polaris) is indicated there as a star of the 3-rd magnitude. Let us explain that of course it the Almagest, the modern Alpha and Beta-convention was not used and the stars were indicated according to their position in the constellation and the coordinates. In fact, the brightness of the both Alpha and Beta stars in the Ursa Minor constellation are almost identical. Based on the present day measurements, the brightness of Alpha is M = +2.1 and of Beta is M = +2.2 (see section 6.8 for more information about the brightness scale), which means that Alpha is just slightly brighter than Beta. Nevertheless, Ptolemy mistakenly thought opposite.

Figure 1.15: Locations of Alpha Ursae Minoris and Beta Ursae Minoris with respect to the North Pole.

Moreover, the computations show that in the 2nd century A.D. the distance between Beta Ursae Minoris and the north pole was exactly 8o, which is exactly the same

as the distance between Alpha Ursae Minoris (North Star) and the north pole today. In the 2nd century Alpha was located 12o from the north pole. That means that it could be clearly noticed that in the 2nd century the North Star was significantly further from the north pole than Beta Ursae Minoris. The actual configuration of these stars, as it was observed in the 2nd century, is shown on Figure 1.14 which is based on a chart made by German astronomer Johann E. Bode according to the Almagest. As Bode was not concerned with the actual dating of the Almagest, his drawing indicates the actual locations of the stars in the 2nd century. Notice that, Beta is indicated in the center of Ursa Minor, while Alpha is placed at the very end of the tail of this constellation. This is exactly how the positions of these two stars were described in the Almagest: Alpha as "the star at the end of the tail," and Beta as "the most northern star in the back of the constellation."

In our opinion, it would be the most reasonable to start the 2nd century star catalogue with the star Beta rather than Alpha. N.A. Morozov wrote in this respect:

" "Who possibly could have an idea to present a description of constellations in the northern hemisphere beginning with the most distant from the north pole star of the Ursa Minor, which was not even in the center of this constellation but at its very end of the tail."

However, all these peculiarities disappear when we renounce the hypothesis claiming that the Almagest was compiled in the beginning of the Christian era. Let us find out what would be the best epoch, in which Northern Star was the most natural choice for the first star in the catalogue. On Figure 1.15 we show the trajectory of the north pole around the ecliptic pole P, and the locations of the stars Alpha and Beta. It is clear that with the time the astronomical situation was changing: Beta was gradually moving away from the north pole, while Alpha was directly approaching the north pole. We have indicated on Figure 1.15 the initial position N of the north pole in the 2nd century A.D. The angular velocity of the north pole moving around the ecliptic is about 1o per 100 years. Now, we are in the position to find out the epoch when North Star became closer to the North Pole than the star Beta. Since an argument of this type can hardly be considered as reliable for the dating purposes, we are satisfied with a rough estimate indicating the period from the 9th to 11th century A.D. At that time Alpha was closer to the north pole than Beta and Alpha was also the brightest star of Ursa Minor (M = +2.1 for Alpha, while for Beta it was M = +2.2). It is also obvious that at that time an observer compiling a star catalogue, would choose the star Alpha as the first star in the Northern Hemisphere. Notice that it is exactly, how the creator of the Almagest listed the stars. In addition, during the 15th and 16th centuries, when the publications of the Almagest took place, North Star was the closest star to the north pole — its distance was only 4o from the north pole. Consequently, by choosing North Star as the first star in the catalogue, the creator of the Almagest revealed the real time of its observations — the epoch that was not earlier than the 9th or 10th century.

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The Illustrated Key To The Tarot

The Illustrated Key To The Tarot

The pathology of the poet says that the undevout astronomer is mad the pathology of the very plain man says that the genius is mad and between these extremes, which stand for ten thousand analogous excesses, the sovereign reason takes the part of a moderator and does what it can. I do not think that there is a pathology of the occult dedications, but about their extravagances no one can question, and it is not less difficult than thankless to act as a moderator regarding them.

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