Cygnus

Definition

Cygnus is a northern constellation pictured as a swan flying along the Milky Way. It is one of the 48 constellations catalogued in Ptolemy's Almagest, where it belongs to the northern group rather than the zodiac; older Mesopotamian star-lore charted the figure on the Euphrates, and in Greek myth the swan is linked to Zeus.

In Tradition

Cygnus sits among the fixed northern constellations outside the zodiacal band, so across the Greek and Arabic traditions it carries no sign-rulership or house meaning of its own. Like other non-zodiacal figures it enters a chart only through the bright stars within it, which are read in the fixed-star manner when one of them falls close to a planet or an angle by longitude.

In Practice

In practice Cygnus is a backdrop constellation rather than a technique. It becomes interpretively live only when one of its stars conjoins a planet or chart angle within a tight orb, at which point that star's traditional nature is folded into the delineation; otherwise the figure serves mainly to locate stars and map the northern sky rather than acting as a factor in its own right.

Historical Origin

Cygnus is one of the twenty-one northern figures in Ptolemy's 48-constellation catalogue. Abu Ma'shar's Great Introduction (Part II, sections 1.7a-1.10) transmits that list to the medieval Arabic world, where the constellation is named 'the Hen.' The swan imagery and the older Euphratean charting of the figure are traced in Bernadette Brady's modern fixed-star work.

Etymology

Origin: Latin. Meaning: Cygnus is Latin for 'swan' (from Greek kyknos); in the Arabic transmission of Ptolemy the same figure was called 'the Hen.'.

Further Reading

• Abu Ma'shar, The Great Introduction to the Science of the Judgements of the Stars, Part II, sections 1.7a-1.10 (the 48 Ptolemaic constellations)
• Bernadette Brady, Brady's Book of Fixed Stars