Circumpolar Star

Definition

A star whose apparent diurnal path stays entirely above the horizon at a given observer's latitude, so that the star never rises and never sets — it circles the celestial pole continuously, visible throughout the year on a clear night. The set of circumpolar stars varies with latitude: the closer the observer is to the pole, the more stars are circumpolar.

In Tradition

Across the early sky-watching traditions circumpolar stars were read as the celestial figures that 'do not die' — the never-setting markers of the cosmos's stable axis, in contrast to the ecliptic bodies that rise and set. The Egyptian tradition gave this register its most explicit theological elaboration; Babylonian and Hellenistic astronomy preserved it as a technical category.

In Practice

When you locate a chart's polar-axis figures in a culture that uses circumpolar imagery, you look to the constellations around the pole — Ursa Major, Ursa Minor, Draco, Cassiopeia for a northern observer — and treat them as the structural backdrop against which the ecliptic bodies move. In Egyptian funerary religion the imperishable stars are associated with the king's post-mortem destiny: never-setting was read as never-dying. In modern fixed-star practice circumpolar stars (Polaris, the Big Dipper stars, Capella in the far north) appear chiefly through their declination-based parans rather than ecliptic conjunctions.

Historical Origin

The Egyptian term ikhemu sekiu (jxmw skj(w), 'those who do not know destruction') is attested from the Pyramid Texts (Old Kingdom, c. 2400-2300 BCE) and named in Belmonte and Lull's Glossary as the imperishable circumpolar stars. Meskhetyu (the Big Dipper / Bull's Foreleg) was the imperishable constellation par excellence. Babylonian astronomical lists distinguished the celestial paths of Anu, Enlil, and Ea; circumpolar stars belonged to the Path of Enlil. The category remained operative in Greek and later astronomical work.

Etymology

Origin: Latin / Greek. Meaning: Latin circum- ('around') + polaris ('of the pole'); literally 'around-the-pole.' Egyptian ikhemu sekiu, literally 'those who do not know destruction.'.

Further Reading

• Juan Antonio Belmonte & José Lull, Astronomy of Ancient Egypt
• Bernadette Brady, Brady's Book of Fixed Stars