An imaginary line around the sky directly above the equator. See celestial sphere for a helpful diagram.
A great circle on the celestial sphere 90° from the celestial poles; where the celestial sphere intersects the plane of the Earth's equator.
The equator in the sky that corresponds to the equator on Earth.
A line in the sky directly above the Earth's equator.
an imaginary line running among the stars that is in the same plane as the earth's equator.
the plane perpendicular to the celestial ephemeris pole. Colloquially, the projection onto the celestial sphere of the Earth's equator. (See mean equator and equinox: true equator and equinox.)
The line representing the point halfway between the north celestial pole and the south celestial pole. On the astrolabe, it is represented by the dark circle passing through east and west on the horizon.
great circle that is a projection of the Earth's equator onto the sky. Always intercepts horizon at exact East and exact West point. Its meridian altitude = 90\deg -- observer's latitude. We see one-half of its circle at a time (12 hours worth).
A great circle, halfway between the Celestial Poles, dividing the sky into northern and southern halves. Used as the starting point for measurement of declination. Analogous to the Equator in the Terrestrial coordinate system.
a intersection of the (instant) Globe equatorial plane by using the celestial sphere
The equinoctial, that equatorial band made by projecting the earth's equator into the celestial sphere.
the Earth's equator projected onto the sky
zero point for declination; directly above Earth's equator
The great circle marking the halfway point between the celestial poles. The celestial equator is Earth's equator extended outward against the celestial sphere. Any object along the celestial equator has a declination of 0 degrees. The belt stars in Orion reside along the celestial equator and can be seen throughout the civilized world.
The projection of the equatorial plane of Earth on the celestial sphere.
A line around the celestial sphere which divides its northern and southern hemispheres.
The projection of Earth's equator into space. Also a line in the sky midway between the north and south celestial poles. The celestial equator is the line of zero declination in the equatorial coordinate system.
A great circle on the celestial sphere marking a boundary between northern and southern hemispheres.
The projection of the plane of the geographical equator upon the celestial sphere.
The great circle on the celestial sphere marking the boundary between the northern and southern hemispheres, and acting as the zero-marl for declination. It is the projection into space of the Erath's equatorial plane.
the great circle of the celestial sphere all points of which are 90 degrees from the poles. It is the plane of the Earth's equator projected onto the celestial sphere.
The projection of the Earth's equator upon the celestial sphere.
An imaginary line that divides the celestial sphere into a northern and southern hemisphere.
The great circle of the celestial sphere, dividing the northern and southern hemispheres, which is located 90 degrees from the poles and is projected onto the celestial sphere directly above the earth's equator.
The great circle on the celestial sphere projected into the sky midway between the celestial poles.
The great circle on the celestial sphere midway between the celestial poles (the projection of the north and south pole onto the celestial sphere).
An imaginary line around the sky which is directly above the earth's equator.
great circle that represents the projection of Earth's equator onto the sky (celestial sphere).
the projection onto the sky of the Earth's equator
The earth's equator projected on to the Celestial Sphere.
An imaginary projectionof the earth's pole onto the celestial sphere;a point about which the apparent daily rotation of the stars takes place.
The extension of Earth's equator into space, perpendicular to Earth's axis.
The imaginiary line around the sky directly above the Earth's equator.
The projection onto the Celestial Sphere of the Earth's equator in the same plane as the Earth's equator, in other words, the projection of the Earth's equator onto the sky. The Sun crosses the Celestial equator twice a year, creating the seasons as we know them.
A great circle on the celestial sphere that is midway between the two poles of rotation. It really amounts to the projection of the Earth's equator onto the sky. It can be thought of as an imaginary ring, 90 degrees from either pole in the sky.
The celestial equator is a great circle on the imaginary celestial sphere, which is actually the plane of the terrestrial equator extended out into the universe (i.e., it could be constructed by extrapolating the Earth's equator until it touches the celestial sphere). The celestial equator is inclined by ~23.5Â°, with respect to the ecliptic plane; a result of axial tilt.