The decans (; Egyptian b?ktw or baktiu, "[those] connected with work") are 36 groups of stars (small constellations) used in the ancient Egyptian astronomy to conveniently divide the 360 degree ecliptic into 36 parts of 10 degrees each, both for theurgical and helialical horological purposes. The decans each appeared, geocentrically, to rise consecutively on the horizon throughout each daily earth rotation. The rising of each decan marked the beginning of a new decanal "hour" (Greek h?ra) of the night for the ancient Egyptians, and they were used as a sidereal star clock beginning by at least the 9th or 10th Dynasty (c. 2100 BCE).
Because a new decan also appears heliacally every ten days (that is, every ten days, a new decanic star group reappears in the eastern sky at dawn right before the Sun rises, after a period of being obscured by the Sun's light), the ancient Greeks called them dekanoi (?; pl. of ? dekanos) or "tenths".
Decans gave way to a lunar division of 27 or 28 lunar stations, also known as manzil, lunar mansions or nakshatras and thence to a zodiac of 12 signs, based on an anthropomorphic pattern of constellations, and their use can be seen in the Dendera zodiac dated to circa 50 BCE.
Decans continued to be used in astrology in medieval Islam, Renaissance, 17-century astrology, 19-century Theosophy, and in cosmology, astrology, theurgy, and hermeticism, as well as in religion and magic.
Decans first appeared in the 10th Dynasty (2100 BCE) on coffin lids. The sequence of these star patterns began with Sothis (Sirius), and each decan contained a set of stars and corresponding divinities. As measures of time, the rising and setting of decans marked 'hours' and groups of 10 days which comprised an Egyptian year. The ancient Book of Nut covers the subject of the decans.
There were 36 decans (36 × 10 = 360 days), plus five added days to compose the 365 days of a solar based year. Decans measure sidereal time and the solar year is six hours longer; the Sothic and solar years in the Egyptian calendar realign every 1460 years. Decans represented on coffins from later dynasties (such as King Seti I) compared with earlier decan images demonstrate the Sothic-solar shift.
According to Sarah Symons
Although we know the names of the decans, and in some cases can translate the names (?ry-?b w means 'in the centre of the boat') the locations of the decanal stars and their relationships to modern star names and constellations are not known. This is due to many factors, but key problems are the uncertainty surrounding the observation methods used to develop and populate the diagonal star tables, and the criteria used to select decans (brightness, position, relationship with other stars, and so on).
These predictable heliacal re-appearances by the decans were eventually used by the Egyptians to mark the divisions of their annual solar calendar. Thus the heliacal rising of Sirius marked the annual flooding of the Nile.
Eventually this system led to a system of 12 daytime hours and 12 nighttime hours, varying in length according to the season. Later, a system of 24 "equinoctial" hours was used.
After Hellenistic astrology arose in Alexandria, recorded principally in the work of Claudius Ptolemy and Vettius Valens, various systems attributing symbolic significance to decans arose and linked these to the "wandering stars" and the "Lights": the Sun, Moon, Mercury Venus, Mars as well as Jupiter and Saturn. Decans were connected, for example, with the winds, the four directions, the sect (day or night,) male and female, as well as the four humours (elements;) also these were hermetically considered linked with various diseases and with the timing for the engraving of talismans for curing them; with decanic "faces" (or "phases"), a system where three decans are assigned to each zodiacal sign, each covering 10° of the zodiac, and each ruled by a planetary ruler (see Decan (astrology)); and correlated with astrological signs.
Decans are named in various Greco-Egyptian sources, many Hermetic writings, the Testament of Solomon, and the writings of Aristobulus of Paneas. Julius Firmicus Maternus, Cosmas of Maiuma, Joseph Justus Scaliger, and Athanasius Kircher.
Images of the decans are described in Hermetic writings, by the Indian astrologer Var?hamihira, in the Picatrix, and in Japanese writings. Var?hamihira's images of the decans was influenced by Greco-Egyptian, if not Hermetic, depictions of the decans by way of the Yavanajataka. Their role in Japanese astrology may have derived from an earlier Chinese or Indian form possibly from adding the twelve animals of the Chinese zodiac to a list of twenty-four hour stars. They were most common between the Kamakura and Edo periods.
The first original decan position due to the precession in ancient times started at 0° of Cancer when the heliacal rising of Sirius (Egyptian Sepdet; Greco-Egyptian: Sothis) on sunset like Jewish and Islamic calendars marking the Egyptian New Year and now the 1st decan falls on 0° of Leo at July 20 in the Julian calendar, that is July 22/23 on the Gregorian calendar.
|Western Zodiac||Decan||Original Decan Position due to the Precession in Ancient Times||Ancient Egyptian Transliteration [Ptolemaic Variant Transliteration]||Greco-Egyptian||Testament of Solomon||Aristobulus's names||Greek Hermeticism||Latin Hermeticism||Firmicus||Cosmas||Scalinger||Kircher|
|Aries||1||28||?ont-har||Rhyax or Ruax||Bendonc||Chenlachori||Aulathamas||Senator or Asiccan||Aidoneus||Asiccan||Arueris|
|Si-ket||Barsafael||Mensour||Chontaret||Sabaoth||Senacher or Asenter||Persephone||Senacher||Anubis|
|3||30||Xont-?re||Artosael or Arôtosael||Carexon||Siket||Disornafais||Sentacher or Asentacer||Eros||Acentacer||Horus|
|Xau||Horopel||Gisan||Soou||Jaus||Suo or Asicat||Charis||Asicath||Serapis|
|Arat||Kairoxanondalon or Iudal||Tourtour||Aron||Sarnotois||Aryo or Ason||die Horen||Viroaso||Helitomenos|
|Remen-hare||Sphendonael||Ballat||Rhomenos||Erchmubris||Romanae or Arfa||Litai||Aharph||Apophis|
|?osalk||Sphandor||Farsan||Xocha||Manuchos||Thesogar or Tensogar||Thetys||Thesogar||Tautus|
|Uaret||Belbel||Vaspan||Ouari||Samurois||Ver or Asuae||Kybele||Verasua||Cyclops|
|Phu-hor||Kourtael or Kurtaêl||Parquia||Pepisoth||Azuel||Tepis or Atosoae||Praxidike||Tepisatosoa||Titan|
|Cancer||10||1 (= 0' Cancer)||Sepdet
|Sopdet||Metathiax||Panem||Sotheir||Seneptois||Sothis or Socius||Nike||Sothis||Apollun|
|Knum||Saphthorael or Saphathoraél||Hellors||Chnouphos||Charmine||Thiumis or Thumus||Hekate||Thuimis||Mercophta|
|?ar-Knum||Phobothel or Bobêl||Jarea||Chnoumos||Zaloias||Craumonis or Afruicois||Hephaistos||Aphruimis||Typhon|
|Ha-tet||Leroel or Kumeatêl||Effraa||Ipi||Zachor||Sic||Isis||Sithacer||Peroeus|
|Phu-Tet||Soubetti||Hayas||Phatiti||Frich||Futile or Eisie||Sarapis||Phuonisie||Nepenthe|
|Tom||Katrax or Atrax||Angaf||Athoum||Zamendres||Thumis or Thinnis||Themis||Thumi||Isis|
|Uste-bikot||Jeropa or Ieropaêl||Bethapen||Brysous||Magois||Tophicus or Tropicus||Moirai||Thopitus||Pi-Osiris|
|Aposot||Modobel or Buldumêch||Baroche||Amphatham||Michulais||Afut or Asuth||Hestia||Aphut||Cronus|
|Sobos||Madero or Naôth||Zercuris||Sphoukou||Psineus||Seuichut or Senichut||Erinys||Serucuth||Zeuda|
|Tpa-?ont||Nathotho or Marderô||Baham||Nephthimes||Chusthisis||Sepisent or Atebenus||Kairos||Aterechinis||Omphta|
|21||12||Xont-har||Alath||Pieret||Phou||Psamiatois||Senta or Atepiten||Loimos||Arpien||Ophionius|
|Spt-?ne||Audameoth||Haziza||Name||Necbeuos||Sentacer or Asente||Nymphs||Sentacer||Arimanius|
|23||14||Sesme||Nefthada||Nacy||Oustichos||Turmantis||Tepsisen or Asentatir||Leto||Tepiseuth||Merota|
|24||15||Si-sesme||Akton||Alleinac||Aphebis||Psermes||Sentineu or Aterceni(-cem)||Kairos (repeated)||Senicer||Panotragus|
|Hre-ua||Anatreth||Ortusa||Sebos||Clinothois||Eregbuo or Ergbuo||Loimos (repeated)||Eregbuo||Tolmophta|
|26||17||Sesme||Enautha or Enenuth||Daha||Teuchmos||Thursois||Sagon||Kore||Sagen||Tomras|
|Konime||Axesbyth or Phêth||Satan||Chthisar||Renethis||Chenene or Chenem||Ananke||Chenen||Teraph|
|Smat||Hapax or Harpax||Eracto||Tair||Renpsois||Themeso||Asklepios||Themeso||Soda|
|Srat||Anoster||Salac||Epitek||Manethois||Epiemu or Epimen||Hygieia||Epima||Riruphta|
|Si-srat||Physikoreth or Alleborith||Seros||Epichnaus||Marcois||Omot||Tolma||Homoth||Monuphta|
|Tpa-?u||Aleureth or Hephesimireth||Tonghel||Isi||Ularis||Oro or Asoer||Dike||Oroasoer||Brondeus|
|Xu||Ichthion||Anafa||Sosomo||Luxois||Cratero or Astiro||Phobos||Astiro||Vucula|
|33||24||Tpa-Biu||Achoneoth or Agchoniôn||Simos||Chonoumous||Crauxes||Tepis or Amasiero||Osiris||Tepisatras||Proteus|
|Pisces||34||25||Biu||Autoth or Autothith||Achaf||Tetimo||Fambais||Acha or Atapiac||Okeanos||Archatapias||Rephan|
|35||26||Xont-Har||Phtheneoth or Phthenoth||Larvata||Sopphi||Flugmois||Tepibui or Tepabiu||Dolos||Thopibui||Sourut|
|36||27||Tpi-biu||Bianakith||Ajaras||Syro||Piatris||Uiu or Aatexbui||Elpis||Atembui||Phallophorus|
Ancient cosmology and astronomy were inextricably bound up with omen lore and hence astrology. Within the many different traditions of astrology that principally arose - more formally out of Alexandria - there are several systems of decans linked to both the traditional Hellenistic five "wandering stars" (Mercury, Venus, Mars, Jupiter and Saturn) and to the two "lights": the Sun and Moon; as well as, more recently, the inclusion of the trans Saturnians: Uranus, Neptune and Pluto). The use of these decans are described in Decan (astrology).
The East Asian zodiac features decans in the form of Thirty-six Calendar Animals (Sanj?roku Kingy?z? ; alternatively known as the Chikusan Reiki ). The group originated in China, wherein the 36 were divided into four clusters, with each cluster made up of nine animal-deity pairs (4 × 9 = 36). The four clusters represent the four cardinal directions (north, south, east, west). The animals are also grouped in triads--three animals are combined under one of 12 Zodiac Signs (3 × 12 = 36). In Japan, the group appeared in the Nich? Reki , a Japanese calendar from the second half of the 14th century. Eight of the 36 appear "fox like"--almost identical in physical attributes. These eight (presented below) include the tanuki, mujna, fox, wolf, jackal, wild cat, and wild male-female dogs. The mujina, fox and rabbit are combined under the zodiacal sign of the rabbit. The tanuki, leopard, and tiger are combined under the zodiacal sign of the tiger. Western scholars have mistranslated tanuki and mujina for decades as "badger" or "racoon-dog." But in extant artwork like that shown below, the beasts are clearly "fox-like." It is therefore puzzling why Western scholars call them badgers and racoon dogs.:
|Zodiac||First animal||Second animal||Third animal|
|Rat||Cat (?)[note 1]||Rat (?)||Bat ()|
|Ox||Cattle (?)||Crab (?)||Turtle (?)|
|Tiger||Raccoon dog (?)[note 2]||Leopard (?)||Tiger (?)|
|Rabbit||Fox (?)[note 3]||Rabbit (?)||Badger (?)[note 4]|
|Dragon||Dragon (?)||Shark (?)||Fish (?)|
|Snake||Cicada (?)||Carp (?)||Snake (?)|
|Horse||Deer (?)||Horse (?)||Roebuck (?)|
|Goat||Sheep (?)||Goose (?)||Hawk or falcon (?)|
|Monkey||Gibbon (?)[note 5]||Ape (?)[note 6]||Monkey (?)[note 7]|
|Rooster||Raven (?)||Chicken (?)||Pheasant (?)|
|Dog||Dog (?, see Inugami)||Wolf (?)||Ch. Dhole, Ja. Honshu wolf (?)|
|Pig||Pig (?)[note 8]||Domestic pig (? ?)[note 9]||Wild boar (?)[note 10]|
The iconography and use of the drekkanas is mention earliest by Sphujidhvaja in Yavanajataka (269-70 CE), and given detailed treatment by Varahamihira in his Brihat-Samhita (550 CE). Modern scholars believe the decans were imported into India through the Greeks, who learned about them from the Egyptians.
The property of the Chaldean Decans that one of them rose every ten days made them fit to be assimilated to the Egyptian decans. This assimilation was performed in the decan lists of Hellenistic astrology.