Angle between magnetic and geographic north.

(astronomy) The circle that consists of all points of a given declination (angle between equatorial plane and a line connecting a specified point with the center of the earth) with radius equal to the distance of the specified point to the center of the earth.

Angle between horizontal and line.

Angle between grid north, magnetic north.

Instrument showing magnetic north deviation.

Circle of constant celestial latitude.

Path celestial bodies follow vertically.