celestial+equator
51equinoxes, precession of the — Motion of the points where the Sun crosses the celestial equator, caused by precession of Earth s axis. Hipparchus noticed that the stars positions were shifted consistently from earlier measures, indicating that Earth, not the stars, was moving …
52Declination — For other uses, see Declination (disambiguation). In astronomy, declination (abbrev. dec or δ) is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. Declination in astronomy is… …
53equinox — /ee kweuh noks , ek weuh /, n. 1. the time when the sun crosses the plane of the earth s equator, making night and day of approximately equal length all over the earth and occurring about March 21 (vernal equinox or spring equinox) and September… …
54List of selected stars for navigation — The selected stars for navigation are often used for sextant observations. Fifty eight selected navigational stars are given a special status in the field of celestial navigation. Of the approximately 6,000 stars visible to the naked eye under… …
55Ecliptic — The ecliptic is the apparent path that the Sun traces out in the sky during the year. As it appears to move in the sky in relation to the stars, the apparent path aligns with the planets throughout the course of the year. More accurately, it is… …
56Zodiac — See also: Zodiac (disambiguation) Wheel of the zodiac: This 6th century mosaic pavement in a synagogue incorporates Greek Byzantine elements, Beit Alpha …
57Geodesy — (pronEng|dʒiːˈɒdɪsi [OED] ), also called geodetics, a branch of earth sciences, is the scientific discipline that deals with the measurement and representation of the Earth, including its gravitational field, in a three dimensional time varying… …
58telescope — /tel euh skohp /, n., adj., v., telescoped, telescoping. n. 1. an optical instrument for making distant objects appear larger and therefore nearer. One of the two principal forms (refracting telescope) consists essentially of an objective lens… …
59Earth — This article is about the planet. For other uses, see Earth (disambiguation). Earth   …
60Circumpolar star — The northern circumpolar stars revolving around the north celestial pole. Note that Polaris, the bright star near the center, is almost stationary. Polaris is circumpolar and can be seen at all times of the year. (The graphic shows how the… …
