Deffinitions - Zenith The point on the celestial sphere...

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Zenith – The point on the celestial sphere vertically overhead. Nadir - The point 180 degrees from the zenith. Horizon – The great circle of the celestial sphere midway between the zenith and nadir, or a line resembling or approximating such a circle. The line were earth and sky appear to meet, and the projection of this line upon a celestial sphere, is called the visible or apparent horizon. Altitude Circle (parallel of altitude) – A circle of the celestial sphere parallel to the horizon, connecting all points of equal altitude. Altitude – angular distance above the horizon; the arc of a vertical circle between the horizon and a point on the celestial sphere, measured upward from the horizon. Zenith distance – the angular distance from the zenith; the arc of a vertical circle between the zenith and a point on the celestial sphere, measured from the zenith through 90 degrees, for bodies above the horizon. This is the same as Coaltitude with reference to the celestial horizon. Vertical Circles
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This note was uploaded on 04/18/2008 for the course DECK DN121 taught by Professor Hall/jablonski/sanborn during the Spring '08 term at United States Merchant Marine Academy.

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Deffinitions - Zenith The point on the celestial sphere...

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