Star clock

Egyptian star clocks were used for astronomical timekeeping in Ancient Egypt. The first occupied in the meantime the first model of Diagonalsternuhr used for the dean star next to the famous instruments of the heliacal Aufgangs additionally as time measurement criterion akronychischen culminations and akronychischen Star sunsets. The determined single hour of the night had, in contrast to the later Ramesside following Nocturnal on a different length. Moreover, in the Diagonalsternuhr acted deans, including the associated Dean stars as basis for calculation.

The Ramesside Nocturnal was based, however, on an hourly stars without explicit dean assignment. In addition, a 13 hour overnight was introduced which allowed a more accurate time measurement. The akronychischen criteria used in the diagonal star clocks experienced an embedding in the new system of star hours. The innovations of the Ramesside Nocturnal could in the long term, however, does not prevail, because due to the extended hours schedule compared to the to the Greco - Roman period traditional twelve-hour system of Diagonalsternuhr lacked the historical basis. Furthermore, the Ramesside Nocturnal was not compatible with the mythology of Imydwat.

• 2.1 Dating the Ramesside Star Clocks

Diagonal Star Clocks

The term Diagonalsternuhr refers to the linear algebra, in which the diagonal marked an imaginary line that runs diagonally from top left to bottom right by the Egyptian calendar schema and thus shows the migration of the Dean -star by the respective weeks.

Discovery

The Egyptologist Ludwig Borchardt was first analyze the methods of the ancient Egyptian time measurement due to of found fragments and coffin fittings. Early on, he noticed that the time measurement in ancient Egypt based primarily on astronomical observations.

Exact calculations in astronomy led to improved interpretations and ways to assign the information of Diagonalsternuhr respect to their time of origin. The first evidence in the form of decorations are tangible in the Middle Kingdom. You are at this time, usually on the undersides of the coffin lid. The oldest occupied diagonal star clocks come from the 9th dynasty. The Diagonalsternuhr located on the coffin lid No. 9 can be dated to the reign of Mentuhotep II in the 11th Dynasty.

Mentioned in the Pyramid texts make use of a diagonal star clocks before the beginning of the Old Kingdom, probably, but can not yet prove. Recent studies have shown that in the Old Kingdom placed the Deans after the heliacal wells and were at the "classic sky picture" oriented. In the Middle Kingdom the climactic deans took the place of the " rising deans ". From this systemic review process, the new order of the Dean of stars emerged in the Coffin Texts.

Sites and assignment of data

Found coffins with diagonal star clocks come from Assiut, Thebes, Gebelein and Aswan. Different arrangements are not visible. These circumstances led to the realization that the details of the diagonal star clocks indicate an idealized calendar. Other astronomical records with calendar reference point to the places Memphis and Heliopolis, why establish the details of the diagonal star clocks most likely uniformly to the 30th degree of latitude.

In the oldest documents of the Middle Kingdom of the heliacal rising of the star Sothis dated in the twelfth hour of the night as the 18th dean, which corresponds to the equivalent of 21 Peret II. The Sothic date confirmed the contents of the coffin texts, after which the Dean sunrises determined the respective hours. The later dating conjunction with the culmination was demonstrably not applied at this time, as the calendar information would then no longer be in accordance with the actual wells.

Operation

Otto Neugebauer, Richard Anthony Parker and Christian Leitz showed that the methods of Dean Stern calculation of the Greco- Roman period and the Middle Kingdom did not meet. In the former case were already introduced twelve signs of the zodiac from Dendera as the basis, which is why hosted the allocation of 36 deans and their night hours on the ecliptic. In the Middle Kingdom, neither the knowledge of the ecliptic nor the basis of the twelve signs of the zodiac was present. The principle of operation of the diagonal star clocks based therefore on a different basis.

On the illustrations and decorations of the tombs of the life cycle of the deities and Dean star was captured by the calendar. Together with the instrument of shadow clock divided the Egyptians the day in the twelve hours of the day and the twelve hours of the night, the length of the daylight hours of the sun of the day was dependent. The night hours were divided into aequale time units that have been adjusted in duration of the season. So that the night had twelve individually hours of equal length sections, but no longer coincided with those of the following day.

The Dean -star always showed at the end of each hour; example was the heliacal rising of Sirius according classification of Diagonalsternuhr always at the end of the twelfth hour of the night, ideally as 18 Dean star. Christian Leitz refers to the contradictory assumptions of Otto Neugebauer and Richard Anthony Parker, who equate any hour of the night the diagonal star clocks with 10 ° of the ecliptic against their own definition. The corresponding calculations in conjunction with the ecliptic are based on a non-existent basis and therefore do not apply.

Dean star

In Egyptian astronomy, the year of the Egyptian calendar was divided into 36 weeks with ten days. The missing five days formed the small year. The weeks were associated with Dean - stars, with their heliacal rising to 36 weeks gave their name at a distance of ten days.

Classification of Heaven

Between the first heliacal rising and culminating akronychisch Dean star, which makes the first hour of the night, there are twenty Dean stars. The Dean - stars of heaven ( Sebau -en- pet) had dedicated sky positions.

Eight Dean star are always located in the east and symbolize the birth star ( meset ), nine dean - stars represent the dying stars ( Sheni - duat ) represents the west, while twelve Dean star in the middle of the sky as working dean -star ( Baktiu ) are positioned.

Underworld

In the underworld ( Sheol ) each seven dead star ( shell- Tuat ) held on. The dead star had no specific duties, but slept with the dead together until the next rebirth.

Ramesside Star Clocks

The four specimens from the tombs of Ramses VI. , Ramses VII, and Ramses IX obtained. could be assembled into a largely complete version. A Ramesside Nocturnal contains 24 panels, one each for the first and 16th day of the month of the comprehensive twelve months ancient Egyptian calendar year. The single panel is divided in 13 hours line, which stood for the period from sunset to sunrise. The first line symbolized the beginning of the night, which began just after sunset. The two lines 13 to represent the respective end of twelve hours of the night.

The single hour line contains three entries: Hour, Star name and position information. The stars were either part of an ancient Egyptian constellation or made a single star represents the Ramesside star clocks included a total of 47 different stars. The position information related to the seven possible combinations right shoulder, right ear, right eye, center, left eye, left ear and left shoulder. The center position was for the meridian; the other six data related to the location east and west of the meridian.

Dating of the Ramesside Star Clocks

Due to the constellations described in the Ramesside star clocks already recognized the Egyptologists of the 19th century that the information must relate to a time 1500-1450 BC. Otto Neugebauer and Richard Anthony Parker, who confirmed that period, make an attempt a mapping of the respective stars. After thorough analysis of both Egyptologists came to the conclusion that a precise identification of the individual star positions and thus to a more precise dating is not possible.

Christian Leitz was the first Egyptologist, who thoroughly grappled with the statements by Otto Neugebauer and Richard Anthony Parker regarding the Ramesside star clocks. His findings demonstrate that some star assignments were in error and therefore an accurate chronology scaffold could not be created. Since Seba -en- Saw main star of the ancient Egyptian constellation Sah, in the meantime could be reliably identified and Seba -en- Saw is also included in the grave of the Senmut ceiling in the representations, a day-definite assignment was possible. In the grave of Senmut is noted that Seba -en- Saw culminated on 23 Achet III to midnight. The grave of Senmut constellations mentioned in the appeal as well as in other ancient Egyptian sources on the observation Memphis.

Rolf Krauss, who postulated the hypothesis of changing observation sites, on the other hand, an identification of Seba -en- Saw with Rigel refuses, because in his published analyzes Elephantine is favored as the observation site. An acceptance of the equation of Seba -en- Saw with Rigel would imply the invalidity of his concept. In the Ramesside star clocks, which emerged only about three centuries later, dip the unchanged data from the grave of Senmut on again, although the star positions had moved more than two months in the ancient Egyptian calendar. Astronomical calculations showed that the midnight culmination of Seba -en- Saw in connection of the other star is to bring data only for the years 1463/1462 BC with the ancient Egyptian calendar, and the observation Memphis consistent.