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Ancient Egyptian origins

Decans first appeared in the 10th Dynasty (2100 BCE) on coffin lids.⁴ 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),⁵ 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 (ḥry-ỉb wỉꜣ 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).⁶

Later developments

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.

This method led to a system of 12 daytime hours and 12 nighttime hours, varying in length according to the season. Later,[when?] a system of 24 "equinoctial" hours was used.⁷ 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" (Mercury, Venus, Mars, Jupiter and Saturn) and the "Lights": (Sun and Moon).⁸ 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;⁹ 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.¹⁰

Descriptions of the decans

Decans are named in various Greco-Egyptian sources, many Hermetic writings, the Testament of Solomon,¹¹ the Tabula Aristobuli (Codex Palatinus) attributed to Aristobulus of Paneas,¹² and the writings of Julius Firmicus Maternus, Cosmas of Maiuma, Joseph Justus Scaliger, and Athanasius Kircher.¹³

Images of the decans are described in Hermetic writings, by the Indian astrologer Varāhamihira, in the Picatrix, and in Japanese writings.¹⁴ Varāhamihira's images of the decans was influenced by Greco-Egyptian, if not Hermetic, depictions of the decans by way of the Yavanajataka.¹⁵ Their role in Japanese astrology may have derived from an earlier Chinese¹⁶ or Indian form¹⁷ possibly from adding the twelve animals of the Chinese zodiac to a list of twenty-four hour stars.¹⁸ They were most common between the Kamakura and Edo periods.¹⁹

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) before sunrise marking the Egyptian New Year which fell at 0° of Leo at July 20 in the Julian calendar, that is July 22/23 on the Gregorian calendar.

Ancient India

Main article: Drekkana

In India, the division of the zodiac into 36 ten degree portions is called either the drekkana (drekkāṇa), the dreshkana (dreṣkāṇa), or the drikana (dṛkāṇa).³⁹

The iconography and use of the drekkanas is mention earliest by Sphujidhvaja in Yavanajataka (269–270 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.⁴⁰

See also

• Asterism (astronomy)
• Astronomical ceiling of Senemut Tomb
• Behenian fixed star
• Chinese zodiac
• Palazzo Schifanoia, Ferrara
• Worship of heavenly bodies

Works cited

• Budge, E. A. Wallis (1904). The gods of the Egyptians; or, Studies in Egyptian mythology. Chicago: Open Court Publishing Co.
• Conybeare, Frederick Cornwallis (tr.)  (October 1898). "The Testament of Solomon". The Jewish Quarterly Review. XI (1 ): 1–45 . doi:10.2307/1450398 . JSTOR 1450398. {{cite journal}}: no-break space character in |doi= at position 16 (help); no-break space character in |first= at position 27 (help); no-break space character in |issue= at position 2 (help); no-break space character in |pages= at position 5 (help)
• Gundel, Wilhelm (1936). Dekane und Dekansterbilder (in German). Glückstadt and Hamburg: J. J. Augustin.
• Hermes Trismegistus (1993). Hand, Robert (ed.). Hermes: Liber Hermetis Part I and Part II. Translated by Robert Zoller (1st ed.). Berkeley Springs, WV: Golden Hind Press.
• Julius Firmicus Maternus (1968) [336]. Kroll, W.; Skutsch, F. (eds.). Matheseos libri VIII (in Latin). Stuttgart: Teubner. 2 vols.
• Keyser, Paul; Scarborough, John (2018). The Oxford Handbook of Science and Medicine in the Classical World. Oxford University Press. ISBN 978-0190878832.
• Kircher, Athanasius (1652). Oedipus Aegyptiacus (in Latin). Italy: Vitale Mascardi.
• Michio, Yano (2008). "Bukkyō tenbugaku-senseijutsu no zuzō gakuteki junmen: sanjū rokkin to Dekan". Dōshisha daigaku rikō kenkyū hōkoku (in Japanese). 48 (4): 1–6.
• Neugebauer, Otto (1969) [1957]. The Exact Sciences in Antiquity (2nd ed.). Dover Publications. ISBN 978-0-486-22332-2.
• Neugebauer, Otto (1983) [1955]. "The Egyptian 'Decans'". Astronomy and History: Selected Essays. New York: Springer. pp. 205–209. doi:10.1007/978-1-4612-5559-8. ISBN 978-0-387-90844-1.
• Pingree, David (1963). "The Indian Iconography of the decans and Horas". Journal of the Warburg and Courtauld Institutes. 26 (3/4): 223–254. doi:10.2307/750493. JSTOR 750493. S2CID 194974629.
• Priskin, Gyula (2016). "The Astral Myth of Osiris: the Decans of Taurus and Libra" (PDF). ENiM (9): 79–111. Retrieved 2021-07-08.
• Ptolemy (1940). Tetrabiblos. Vol. Book I Part 18. Translated by Frank Egleston Robbins. Cambridge, MA: Loeb.
• Ruelle, C. E. (October 1908). "Hermès Trismégiste: Le Livré Sacre sur les Décans: Texte, variantes et traduction française". Revue de Philologie (in French). 32 (4): 247–277.
• Symons, S. L. (2007). "A Star's Year: The Annual Cycle in the Ancient Egyptian Sky". In Steele, J. M. (ed.). Calendars and Years: Astronomy and Time in the Ancient World. Oxford: Oxbow Books. pp. 1–33. ISBN 978-1842173022. Archived from the original on 2013-06-15.
• Symons, S. L.; et al. (2013). "Diagonal Star Tables". Ancient Egyptian Astronomy (Online database).
• van der Waerden, B. L. (January 1949). "Babylonian Astronomy. II. The Thirty-Six Stars". Journal of Near Eastern Studies. 8 (1): 6–26. doi:10.1086/370901. JSTOR 542436. S2CID 222443741. 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.
• von Bomhard, Anna-Sophie (1999). The Egyptian Calendar: A Work for Eternity. London: Periplus.

Further reading

• Christian, Paul (1969) [1870]. "The Thirty-Six Decans". The History and Practice of Magic. Citadel. pp. 476–478.
• Symons, Sarah (2014). "Egyptian 'Star Clocks'". In Ruggles, Clive L.N. (ed.). Handbook of Archaeoastronomy and Ethnoastronomy. New York: Springer. pp. 1495–1500. ISBN 978-1-4614-6140-1.

External links

• Ancient Egyptian Astronomy Database (Symons, Cockcroft, Bettencourt & Koykka, 2013)
• Egypt Astronomy/Astrology: The decans

References

1. Keyser & Scarborough 2018, p. 79. - Keyser, Paul; Scarborough, John (2018). The Oxford Handbook of Science and Medicine in the Classical World. Oxford University Press. ISBN 978-0190878832. ↩

2. Ptolemy 1940. - Ptolemy (1940). Tetrabiblos. Vol. Book I Part 18. Translated by Frank Egleston Robbins. Cambridge, MA: Loeb. ↩

3. Priskin 2016. - Priskin, Gyula (2016). "The Astral Myth of Osiris: the Decans of Taurus and Libra" (PDF). ENiM (9): 79–111. Retrieved 2021-07-08. http://www.enim-egyptologie.fr/revue/2016/7/Priskin_ENiM9_p79-111.pdf ↩

4. Symons 2013. - Symons, S. L.; et al. (2013). "Diagonal Star Tables". Ancient Egyptian Astronomy (Online database). http://aea.physics.mcmaster.ca/index.php/en/database/diagonal-star-tables ↩

5. von Bomhard 1999, p. 51. - von Bomhard, Anna-Sophie (1999). The Egyptian Calendar: A Work for Eternity. London: Periplus. ↩

6. Symons 2007. - Symons, S. L. (2007). "A Star's Year: The Annual Cycle in the Ancient Egyptian Sky". In Steele, J. M. (ed.). Calendars and Years: Astronomy and Time in the Ancient World. Oxford: Oxbow Books. pp. 1–33. ISBN 978-1842173022. Archived from the original on 2013-06-15. https://web.archive.org/web/20130615213439/http://www2.le.ac.uk/Members/sls25/paperstarsyear/ ↩

7. Neugebauer 1983, pp. 205–209; Neugebauer 1969, pp. 81–88. - Neugebauer, Otto (1983) [1955]. "The Egyptian 'Decans'". Astronomy and History: Selected Essays. New York: Springer. pp. 205–209. doi:10.1007/978-1-4612-5559-8. ISBN 978-0-387-90844-1. https://doi.org/10.1007%2F978-1-4612-5559-8 ↩

8. van der Waerden 1949. - van der Waerden, B. L. (January 1949). "Babylonian Astronomy. II. The Thirty-Six Stars". Journal of Near Eastern Studies. 8 (1): 6–26. doi:10.1086/370901. JSTOR 542436. S2CID 222443741. 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. https://doi.org/10.1086%2F370901 ↩

9. Ruelle 1908, p. 247. - Ruelle, C. E. (October 1908). "Hermès Trismégiste: Le Livré Sacre sur les Décans: Texte, variantes et traduction française". Revue de Philologie (in French). 32 (4): 247–277. ↩

10. Julius Firmicus Maternus 1968, IV/22. - Julius Firmicus Maternus (1968) [336]. Kroll, W.; Skutsch, F. (eds.). Matheseos libri VIII (in Latin). Stuttgart: Teubner. ↩

11. Gundel 1936, pp. 77–81. - Gundel, Wilhelm (1936). Dekane und Dekansterbilder (in German). Glückstadt and Hamburg: J. J. Augustin. ↩

12. Gundel 1936, pp. 406–408. - Gundel, Wilhelm (1936). Dekane und Dekansterbilder (in German). Glückstadt and Hamburg: J. J. Augustin. ↩

13. Gundel 1936, pp. 77–81. - Gundel, Wilhelm (1936). Dekane und Dekansterbilder (in German). Glückstadt and Hamburg: J. J. Augustin. ↩

14. Gundel 1936, pp. 223–225. - Gundel, Wilhelm (1936). Dekane und Dekansterbilder (in German). Glückstadt and Hamburg: J. J. Augustin. ↩

15. Pingree 1963. - Pingree, David (1963). "The Indian Iconography of the decans and Horas". Journal of the Warburg and Courtauld Institutes. 26 (3/4): 223–254. doi:10.2307/750493. JSTOR 750493. S2CID 194974629. https://doi.org/10.2307%2F750493 ↩

16. Gundel 1936, pp. 217–221. - Gundel, Wilhelm (1936). Dekane und Dekansterbilder (in German). Glückstadt and Hamburg: J. J. Augustin. ↩

17. Michio 2008. - Michio, Yano (2008). "Bukkyō tenbugaku-senseijutsu no zuzō gakuteki junmen: sanjū rokkin to Dekan". Dōshisha daigaku rikō kenkyū hōkoku (in Japanese). 48 (4): 1–6. ↩

18. Gundel 1936, pp. 217–221. - Gundel, Wilhelm (1936). Dekane und Dekansterbilder (in German). Glückstadt and Hamburg: J. J. Augustin. ↩

19. Michio 2008. - Michio, Yano (2008). "Bukkyō tenbugaku-senseijutsu no zuzō gakuteki junmen: sanjū rokkin to Dekan". Dōshisha daigaku rikō kenkyū hōkoku (in Japanese). 48 (4): 1–6. ↩

20. Budge 1904, pp. 304–308. - Budge, E. A. Wallis (1904). The gods of the Egyptians; or, Studies in Egyptian mythology. Chicago: Open Court Publishing Co. https://archive.org/details/godsofegyptianso02budg ↩

21. Budge 1904, pp. 304–308. - Budge, E. A. Wallis (1904). The gods of the Egyptians; or, Studies in Egyptian mythology. Chicago: Open Court Publishing Co. https://archive.org/details/godsofegyptianso02budg ↩

22. Gundel 1936, pp. 77–81. - Gundel, Wilhelm (1936). Dekane und Dekansterbilder (in German). Glückstadt and Hamburg: J. J. Augustin. ↩

23. Gundel 1936, pp. 77–81. - Gundel, Wilhelm (1936). Dekane und Dekansterbilder (in German). Glückstadt and Hamburg: J. J. Augustin. ↩

24. Gundel 1936, pp. 49–62. - Gundel, Wilhelm (1936). Dekane und Dekansterbilder (in German). Glückstadt and Hamburg: J. J. Augustin. ↩

25. Conybeare 1898. - Conybeare, Frederick Cornwallis (tr.)  (October 1898). "The Testament of Solomon". The Jewish Quarterly Review. XI (1 ): 1–45 . doi:10.2307/1450398 . JSTOR 1450398. https://doi.org/10.2307%2F1450398%C2%A0 ↩

26. Gundel 1936, pp. 406–408. - Gundel, Wilhelm (1936). Dekane und Dekansterbilder (in German). Glückstadt and Hamburg: J. J. Augustin. ↩

27. Gundel 1936, pp. 77–81. - Gundel, Wilhelm (1936). Dekane und Dekansterbilder (in German). Glückstadt and Hamburg: J. J. Augustin. ↩

28. Ruelle 1908. - Ruelle, C. E. (October 1908). "Hermès Trismégiste: Le Livré Sacre sur les Décans: Texte, variantes et traduction française". Revue de Philologie (in French). 32 (4): 247–277. ↩

29. Gundel 1936, pp. 374–383. - Gundel, Wilhelm (1936). Dekane und Dekansterbilder (in German). Glückstadt and Hamburg: J. J. Augustin. ↩

30. Gundel 1936, pp. 77–81. - Gundel, Wilhelm (1936). Dekane und Dekansterbilder (in German). Glückstadt and Hamburg: J. J. Augustin. ↩

31. Gundel 1936, pp. 374–383. - Gundel, Wilhelm (1936). Dekane und Dekansterbilder (in German). Glückstadt and Hamburg: J. J. Augustin. ↩

32. Hermes Trismegistus 1993, pp. iii-12. - Hermes Trismegistus (1993). Hand, Robert (ed.). Hermes: Liber Hermetis Part I and Part II. Translated by Robert Zoller (1st ed.). Berkeley Springs, WV: Golden Hind Press. https://www.weiserantiquarian.com/pages/books/68073/hermes-trismegistus-robert-hand/hermes-liber-hermetis-part-i-and-part-ii-project-hindsight-latin-track-volume-ii-and-volume-iii?soldItem=true ↩

33. Gundel 1936, pp. 77–81. - Gundel, Wilhelm (1936). Dekane und Dekansterbilder (in German). Glückstadt and Hamburg: J. J. Augustin. ↩

34. Gundel 1936, pp. 77–81. - Gundel, Wilhelm (1936). Dekane und Dekansterbilder (in German). Glückstadt and Hamburg: J. J. Augustin. ↩

35. Gundel 1936, pp. 353–354. - Gundel, Wilhelm (1936). Dekane und Dekansterbilder (in German). Glückstadt and Hamburg: J. J. Augustin. ↩

36. Gundel 1936, pp. 77–81. - Gundel, Wilhelm (1936). Dekane und Dekansterbilder (in German). Glückstadt and Hamburg: J. J. Augustin. ↩

37. Gundel 1936, pp. 77–81. - Gundel, Wilhelm (1936). Dekane und Dekansterbilder (in German). Glückstadt and Hamburg: J. J. Augustin. ↩

38. Kircher 1652, pp. 182–186, Tome 2. - Kircher, Athanasius (1652). Oedipus Aegyptiacus (in Latin). Italy: Vitale Mascardi. ↩

39. Monier Williams Sanskrit Dictionary[full citation needed] /wiki/Wikipedia:Citing_sources#What_information_to_include ↩

40. Pingree 1963. - Pingree, David (1963). "The Indian Iconography of the decans and Horas". Journal of the Warburg and Courtauld Institutes. 26 (3/4): 223–254. doi:10.2307/750493. JSTOR 750493. S2CID 194974629. https://doi.org/10.2307%2F750493 ↩