CELESTIAL NAVIGATION( 2)

                                                              CELESTIAL MERIDIA

Are semi great circle on the celestial sphere,the plane of which passes through the celestial poles.These corresponding to the meridians on the earth,celestial meridian cross the equinoctial and all declination circles at right angle.

DECLINATION

Declination of a celestial body is a arc of a celestial meridian,or the angle at the center of the celestial sphere, measured between the equinoctial and the declination circle passing through that body.Declination is expressed as in degrees and minutes north or south from the equinoctial.The declination of a celestial boday must have a value between 0 and 90 degrees North or South.