Assertion: asterism's star | /r/HasProperty | circumpolar
Facets:
value: in one hemisphere
type: LOCATION
value: at the observer's latitude
type: LOCATION
value: at the equator
type: LOCATION
value: once again
type: TEMPORAL
Source sentences:
text: The Big Dipper's seven bright stars — a flat-bottomed basin attached to a bent three-starred handle — are circumpolar, making it visible year-round from mid- northern latitudes.
text: Some stars within the far northern constellation (such as Cassiopeia, Cepheus, Ursa Major, and Ursa Minor) roughly north of the Tropic of Cancer (+23½°) will be circumpolar stars, which never rise or set.
text: Depending on the observer's latitude on Earth, some stars – the circumpolar ones – are close enough to the celestial pole to remain continuously above the horizon, while other stars dip below the horizon for some portion of their daily circular path (and others remain permanently below the horizon).
text: At the Earth's North Pole, the north celestial pole is directly overhead, and all stars that are visible at all (that is, all stars in the Northern Celestial Hemisphere) are circumpolar.
text: This continues until one reaches the Earth's South Pole where, once again, all visible stars are circumpolar.
text: Whether a star is circumpolar depends upon the observer's latitude.
text: For example, if the observer's latitude is 50° N, any star will be circumpolar if it is less than 50° from the north celestial pole.
text: If the observer's latitude is 35° S, then all stars within 35° of the south celestial pole are circumpolar.
text: Whether a given star is circumpolar at the observer's latitude (θ) may be calculated in terms of the star's declination (δ).
text: The star is circumpolar if θ + δ is greater than +90° (observer in Northern Hemisphere), or θ
text: At the equator no star is circumpolar.
text: At the North or South Pole all stars that are visible at all are circumpolar, since only one half of the celestial sphere can ever be seen.
text: Stars (and constellations) that are circumpolar in one hemisphere are always invisible in the high latitudes of the opposite hemisphere, and these never rise above the horizon.
text: Some stars within the far southern constellations (such as Crux, Musca, and Hydrus) roughly south of the Tropic of Capricorn (−23½°) will also be circumpolar stars.