Rukbat

latin: Rukbat · arabic: rukbat al-rāmī (ركبة الرامي)

Definition

Rukbat is the alpha star of the constellation Sagittarius, designated Alpha Sagittarii. Despite its alpha designation Rukbat is one of the fainter named stars of its constellation. The Arabic name rukbat al-rāmī (ركبة الرامي, 'the archer's knee') names the position on the figure where the star sits. In the Hellenistic-Egyptian Hermetic per-degree catalogs Rukbat is fixed at 20°26' Sagittarius with a Saturn-and-Jupiter nature, situated alongside the bright Vega rising at 20°46' Sagittarius in the per-sign sequence.

In Tradition

The Hellenistic-era Hermetic transmission preserved in the Liber Hermetis names Rukbat as one of the per-degree stars of Sagittarius carrying a recorded planetary nature. The Saturn-Jupiter complexion places Rukbat in the same gravity-and-magnification register as El Nath and Alnilam earlier in the zodiac, and as Capella in the Taurus catalog.

In Practice

Astrologers reading Rukbat anchor the star at 20°26' Sagittarius per the Liber Hermetis Chapter III catalog. The Saturn-Jupiter assignment is read as Rukbat's planetary complexion when the star rises, culminates, or conjoins a natal point. Per-degree practice treats the rising minute as the operative threshold: 20°26' Sagittarius in the ascendant is when the Rukbat signification activates. The Liber Hermetis surrounds Rukbat with related per-degree stars — Nu Sagittarii (the eye of Sagittarius, nebulous) at 18°-19°, Vega (Alpha Lyrae, Mercury-Venus nature) at 20°46', and the Uranoscopus 'always praying' at 20°-26° — together composing the per-sign catalog's mapping of mid-to-late Sagittarius. Crane's reference table notes Rukbat's far-southern declination (over 40° south of the equator) as a reason modern practitioners often drop the star from zodiacal-star work, treating it via parallel-of-declination or paranatella rather than direct longitudinal aspect.

Historical Origin

Rukbat is named in the Liber Hermetis Chapter III per-sign fixed-star catalog for Sagittarius, preserved in the Gundel 1936 critical edition and translated by Robert Zoller for Project Hindsight. The Hermetic-corpus text is Hellenistic-era Greek-original (2nd c. BCE - 3rd c. CE) transmitted via Latin redaction. The Arabic name rukbat al-rāmī is medieval Islamic-astronomical, inherited into the Western fixed-star tradition through medieval Latin transmission.

Etymology

Origin: Arabic. Meaning: From Arabic rukbat al-rāmī (ركبة الرامي), 'the knee of the archer', for the star's position on the figure of Sagittarius..

Further Reading

  • Robert Zoller, Liber Hermetis (Project Hindsight)
  • Bernadette Brady, Brady's Book of Fixed Stars
  • Vivian E. Robson, The Fixed Stars and Constellations in Astrology