An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

Situated around or near a pole, as of the Earth or the sky. → circumpolar star.

→ circum-; → polar.

Star that, from a given observer's → latitude, does not rise or set, but circles around the → celestial pole. To be circumpolar, a star must have a polar distance that is less than the observer's latitude. Whether a given star is circumpolar at the observer's latitude (φ) may be calculated in terms of the star's → declination (δ). The star is circumpolar if φ + δ ≥ +90° (observer in northern hemisphere), or φ + δ ≤ -90° (observer in southern hemisphere).

→ circumpolar; → star.