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Astral Atlas
Wiki concept · Modern & historical traditions

Decan

Also called decans

In a zodiacal astrological table, one of three ten-degree divisions of a sign, also called a face; Egyptian stellar decans are a historically distinct calendrical and observational concept.

In this entry

Separate zodiacal faces from Egyptian stellar decans

In the Lilly-style dignity context, ‘face’ or zodiacal decan means one of three equal ten-degree portions inside a sign. It is a longitude classification: after choosing a zodiac, locate the degree in the sign and assign first, second, or third face. Its interpretive ruler, if used, comes from a named astrological table.

Egyptian stellar decans belong to a different historical setting of decanal stars and calendrical timekeeping. The shared word ‘decan’ is not enough to transfer a stellar list, an epoch, a visibility condition, or an interpretation into the zodiacal-face calculation. Name the system before comparing outputs.

William Lilly, Christian Astrology (1647), original printed p104 ↗William Lilly: Christian Astrology (1647), original text, pp. 101–112 ↗Metropolitan Museum: Senenmut astronomical ceiling ↗

Word origin · etymology

Late Latin numerical term.

Decanus meant a leader of ten. The astronomical and astrological label retains this association with ten.

Merriam-Webster: decan ↗

How we know · epistemology

Historically distinct division systems

A zodiacal decan is a reproducible ten-degree partition once a zodiac is named; Egyptian stellar decans arose in a different calendrical and observational setting. Shared terminology does not justify importing one system’s stars, dates, or meanings into the other without identifying the method.

Metropolitan Museum: Senenmut astronomical ceiling ↗Lilly: Christian Astrology, annotated primary text ↗

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Terms used in this explanation

These links connect subjects and terminology. They do not establish a shared historical origin.

Sources & provenance

Use the citations beside each section to distinguish a calculation convention, a historical teaching and an editorial example.

Find these sources across the wiki →

  1. Metropolitan Museum: Senenmut astronomical ceiling ↗
  2. Lilly: Christian Astrology, annotated primary text ↗
  3. Merriam-Webster: decan ↗
  4. William Lilly, Christian Astrology (1647), original printed p104 ↗
  5. William Lilly: Christian Astrology (1647), original text, pp. 101–112 ↗