Dubhe

Definition

Dubhe is the alpha star of Ursa Major, designated Alpha Ursae Majoris, and one of the two pointer-stars that lead the eye from the bowl of the Big Dipper toward Polaris. The Arabic name dubb al-akbar (الدب الأكبر, 'the greater bear') names the constellation, with the star carrying the constellation's designation. In the pre-Hellenistic Egyptian funerary-astronomical tradition Dubhe and its neighbour Kochab anchor the polar end of Meskhetyu, the foreleg or adze-figure that is the Egyptian counterpart of the Plough.

In Tradition

In Egyptian funerary cosmology Dubhe sits within Meskhetyu, the polar asterism whose stars are read as the celestial adzes (nTrwy) used in the Opening of the Mouth ceremony — the iron-bladed (sbAwy) ritual instruments that open the deceased pharaoh's senses for the astral ascent to the ikhemu-sek (imperishable) northern stars. Belmonte and Lull identify Dubhe and Kochab as the precise positions of the two celestial adzes in the asterism of the Plough.

In Practice

Practitioners encounter Dubhe in two distinct reading-frames. In the pre-Hellenistic Egyptian funerary-architectural register the star anchors monumental orientation: Djoser's 3rd-Dynasty Saqqara serdab (c. 2670 BC) is oriented to the lower culmination of Dubhe and Kochab, with sight-channels in the northern façade declination-aligned to the two stars. The Egyptian-Spanish Mission (Shaltout et al. 2007) and Belmonte's 2012 archaeoastronomical analysis date the serdab orientation to 2620-2485 BC by Dubhe-Kochab declination computation. In the modern Western fixed-star tradition Dubhe is read as a circumpolar pointer-star whose far-northern declination places it well outside the standard zodiacal-star reading-band; paranatella and parallel-of-declination work against the Ascendant or Midheaven are the practical readings rather than direct longitudinal conjunction. The Meskhetyu / Plough / Great Bear identification carries through from the Egyptian to the Greek to the Arabic naming-traditions, making Dubhe a continuity-marker across the polar-asterism receptions.

Historical Origin

Dubhe is attested in the Egyptian Pyramid-Texts polar-stars cosmology (Old Kingdom 3rd-6th Dynasties, c. 2670-2200 BCE) via the architectural orientation of Djoser's Saqqara serdab to the declination of Dubhe and Kochab. Belmonte and Lull's 2018 Astronomy of Ancient Egypt records the archaeoastronomical dating (2620-2485 BC) and reads the star as the meteoritic-iron tip of the celestial adze Meskhetyu. The Arabic name dubb al-akbar is medieval Islamic-astronomical, inherited into the Western fixed-star tradition through medieval Latin transmission.

Etymology

Origin: Arabic. Meaning: From Arabic dubb al-akbar (الدب الأكبر), 'the greater bear' — the Arabic name of the constellation Ursa Major transferred to its alpha star..

Further Reading

• Juan Antonio Belmonte & José Lull, Astronomy of Ancient Egypt
• Bernadette Brady, Brady's Book of Fixed Stars
• Vivian E. Robson, The Fixed Stars and Constellations in Astrology