equatorial coordinate system
The coordinate system in which a celestial object’s position on the celestial sphere is described in terms of its declination and right ascension, measured with respect to the celestial equator. Declination and right ascension correspond directly to geographic latitude and longitude as projected outward onto the celestial sphere. Declination is measured in degrees north or south of the celestial equator, the same as geographic latitude, but right ascension is measured in hours, minutes, and seconds eastward along the celestial equator from the point of the vernal equinox. Because the celestial equator moves among the fixed stars with the precession of the Earth’s poles, an object’s declination and right ascension change gradually over time, and coordinates in the equatorial system must be specified for particular years. The equatorial system is the system most used in astronomy for describing the position of objects outside the solar system. Compare altazimuth coordinate system, ecliptic coordinate system.
noun 1. an ocean current that flows E between the west-flowing equatorial currents.
noun 1. a republic in W equatorial Africa, comprising the mainland province of Río Muni and the island province of Bioko: formerly a Spanish colony. 10,824 sq. mi. (28,034 sq. km). Capital: Malabo. noun 1. a republic of W Africa, consisting of Río Muni on the mainland and the island of Bioko in the Gulf […]
- Equatorial mount
equatorial mount A mounting for astronomical telescopes having two axes, one of which revolves about an axis that is parallel to the axis of the Earth’s rotation. This axis can be driven by a motor at a rate equal to the diurnal motion of the celestial object being viewed, allowing the telescope to keep the […]
noun, Cell Biology. 1. the central plane of the spindle in a dividing cell, to which chromosomes migrate during the metaphase of mitosis or meiosis. equatorial plate n. The plane located midway between the poles of a dividing cell during miotic metaphase and touching the centromeres and their spindle attachments.