Schlagwort-Archive: True North

The eight circumpolar stars

Looking in a northerly direction we can see that the circumpolar stars circle a formerly starless North Pole.1. Phase Blickrichtung Norden

On the Nebra Sky Disc its hight above the horizon on the meridian (= imaginary great circle through the North Pole and the South Pole) is defined by the centre of the circuit of the outer circumpolar star, number 8.alle Zirkumpolarsterne

On the computer map the centre of the blue lines corresponds to the northern celestial pole.
The distances between the parallel circles of all the stars of the Sky Disc, marked in light-blue, do not agree with the “distorted” circuits of the stars in the north view of the computer map, but they proportionately fit the altitude angles of the following upper stars: 1 Kocab / Little Bear, 2 η-Draco, 3 Alkaid / Big Bear, 4 Polaris / Little Bear, 5 Etamin / Draco, 6 Alderamin / Kepheus, 7 Alphekka / Northern Crown, 8 Vega / Lyra.

 

Sternenzeiger mit Sechseck im SüdenWenn Zirkumpolarsterne gelichzeitig im Meridian stehen, zeigen Sie als Stenenzeiger den Wahren Norden an oder sie bilden den Stundenzeiger einer Sternenuhr. Present doubts about the validity of the classification are allayed when we have a look at the entire firmament, as in the Early Bronze Age in Central Germany Two seasonal constellations.three of the recognized circumpolar stars were positioned almost vertically on top of one another in the meridian (2 η-Draco, 5 Etamin, 8 Vega), while the constellation from the Winter Hexagon with Deneb and Vega was visible. They form an astral hand.

Two further circumpolar stars (3 Alkaid, 4 Polaris) were located in the meridian exactly six hours later when a triangular constellation occupied the eastern quarter of the sky and Procyon, close to the west point, was just about to set.

This part of a perfect star clock, whose hands circle the North Pole in quarter turns at a distance of exactly six hours, has only been seen for very few centuries in approximately 26.000 years!

 

Nordzeiger Another astral hand, 1 Kocab and 6 Alderamin, might have pointed to True North. “The north was, where the extension of their conection line met the horizon vertically (Kate Spence 2000).” [1]

 

 

 

Presumably the circumpolar star 7 Alphekka was especially important for helping travelers to find their way as it was the brightest star which, after Vega, reached in Central Germany a low position above the True North, as already ascertained.

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[1] www.zeit.de/2000/47/cheops%27_Kompass/seite-3

 

 

Two stars form an astral hand and pointed to True North

Astral hand to True NorthTwo of the recognized eight circumpolar stars, Alderamin (10,8°) und Kocab (43,6°), were crossing formerly the meridian nearly at the same time, when they were positioned almost vertically on top of one another. They form an astral hand that could have shown the True North. Kate Spence, University of Cambridge, has proposed a surprising simple theory, which provides the key to the mysterious orientacion of the pyramids. … the Egyptians could have observed two stars, which were lying approximately in one line to the northern skypole, at that time.
The North was where the extension of their connecting line hit the horizon vertically at night.

 

„The sky was the limit for the Pyramid builders
Dinah Ashman explains how modern astronomy may have put a new date on the building of the Great Pyramid at Giza.

A new theory of how exactly the ancient Egyptians oriented the pyramids according to the stars could put a date on the construction of the Great Pyramid at Giza near Cairo that is accurate within 5 years.
Builders probably got started between 2485 and 2475 BC, Kate Spence of the University of Cambridge, UK, proposes in Nature. Previous estimates have been accurate only to within 100 years. Spence’s idea could enable Egyptologists to refine their chronologies for all the reigns of the Old Kingdom — the middle of the third millennium BC.
“Spence has come up with an ingenious solution to a long-standing mystery,” says Owen Gingerich of the Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts.
The new theory is inspired by the subtle deviations in the alignment of the eight pyramids at Giza from true north. The bases of the earliest-built pyramids point slightly east of north and those of the later-built ones, slightly west. The most precisely aligned pyramid is that of King Khufu or Cheops, also known as the Great Pyramid.
The pyramid builders, Spence suggests, used a pair of fairly bright stars, which in 2467 BC lay precisely along a straight line including the celestial north pole. Each star was about 10 degrees from the pole.
One is Kochab (ï-Ursae Minoris) in the bowl of the Little Dipper (Ursa Minor), the other Mizar (zeta-Ursae Majoris) in the middle of the handle of the Big Dipper (Ursa Major).
“In 2467 BC an Egyptian astronomer could wait while the heavens slowly pivoted around the unmarked pole until a plumb line exactly intersected both stars, one about 10° above the invisible pole and the other 10° below it,” Gingerich explains. The sight line to the horizon point directly below the plumb line would then point straight to north.
Because of the Earth’s precession — the revolving axis of the Earth is unstable and rotates like a gyroscope with a period of 26,000 years — the celestial north pole was exactly aligned between Kochab and Mizar only in the year 2467 BC. Although given the precision of the measurements of the time, the ‘accurate’ period was effectively a few years.
The orientation errors of earlier and later pyramids faithfully track the slow drift of Kochab and Mizar with respect to true north. Because the error in the Kochab-Mizar alignment can be readily calculated for any date, the error in each pyramid’s orientation reveals its construction date [1].” [2]

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[1] Spence, Kate. Ancient Egyptian chronology and the astronomical orientation of pyramids. Nature 408, 320 – 324 .2000
[2] http://www.nature.com/news/2000/001116/full/news001116-10.html    Dinah Ashman