Great circle that crosses the meridian of the birth place at right angles.
The vertical East-West great circle, whose plane is perpendicular to the plane of the meridian, and which passes through the East Point, Zenith, West Point, and Nadir of a particular location. An observer who is standing upright and facing south will be standing in the plane of the prime vertical.
A great circle on the celestial sphere that passes through the zenith. It is a vertical circle that is bisected by the meridian. Degrees run from east to west.
A great circle on the celestial sphere from the east to the west and passing through the zenith.
The vertical plane over an observer that passes directly east-west and straight overhead. One of the fundamental planes defining local space, along with the horizon and the meridian. See also House.
celestial great circle passing through the east and west points and the zenith.
The great circle inscribed on the celestial sphere that passes through the east point, zenith, west point and nadir of any place, ie, the vertical plane over an observer that passes directly east-west and straight overhead.
The great circle that rises vertically from the east point of the horizon and passes through Earth's zenith and nadir.