circumpolar star


Also found in: Wikipedia.

circumpolar star,

star whose diurnal circlediurnal circle
, apparent path followed by a star due to the earth's rotation on its axis. The stars appear to move on the celestial sphere in concentric circular paths centered at the celestial poles.
..... Click the link for more information.
 lies completely above or completely below an observer's horizon. A star whose diurnal circle lies above the horizon never sets, even though it cannot be seen during the day. Designation of a star as circumpolar depends on the observer's latitude. At the equator no star is circumpolar. At the North or South Pole all stars are circumpolar, since only one half of the celestial sphere can ever be seen. For an observer at any other latitude a star whose declination is greater than 90° minus the observer's latitude will be circumpolar, appearing to circle the celestial pole and remaining always above the horizon. A constellation made up entirely of circumpolar stars is also called circumpolar. From most of the N United States (above lat. 40°N) the Big Dipper is circumpolar.

circumpolar star

[¦sər·kəm′pō·lər ′stär]
(astronomy)
A star with its polar distance approximately equal to or less than the latitude of the observer.
References in periodicals archive ?
These stars are known as circumpolar stars and the constellations they belong to are called circumpolar constellations.
Esoteric Egypt" reveals that the ancient Egyptians believed in reincarnation and a spiritual evolutionary process; explains the connections between the movements of Orion and Sirius and the story of Osiris and Isis, the importance of the Pleiades and circumpolar stars to the Egyptians, and the fundamental unity of the Egyptian pantheon; and investigates the people who colonized greater Egypt 100,000 years ago, descendants of the Atlanteans.
Because opposing asterisms can only be found with the help of circumpolar stars, which are always in the sky.
These are known as circumpolar stars and all seem to move in a circular path around the Pole Star (Polaris).
Stars that are near Polaris are called circumpolar stars and can be seen throughout the year.
The farther one is from the Equator, the greater the number of circumpolar stars, which neither rise nor set, but many easily identifiable bodies rise and set during the night, and since they traverse the sky in a plane oblique to the horizon, it is worth being prepared for the first and last opportunities for sighting, and so natural to name those times.
In a more particularly Chinese application of the usefulness of the circumpolar stars, it was evidently also common practice to key their meridian transits to the positions of other stars by means of sight lines, and in this way by indirect means determine the location of the sun, moon, and other heavenly bodies among the lunar mansions not currently visible in the night sky.
Indeed, we know for certain that such techniques were later used by the ancient Chinese, as Joseph Needham has illustrated with regard to the sight-lines established for the circumpolar stars.