equatorial mount

An equatorial mount is a mount used for moving a telescope or camera along two perpendicular axes of motion. These two axes are known as right ascension and declination. The telescope mount's axis of right ascension should be pointed directly towards whichever celestial pole is above the horizon to work correctly. Setting the axis of the mount to the polar axis completes alignment. This polar alignment is dependent on the location of the observer and corresponds with the latitude of the observer's location. Unlike an altazimuth mount, when tracking an object moving across the sky, only one axis needs to be moved instead of both to track the diurnal motion. Also, for astrophotography, the image does not rotate in the focal plane, as occurs with altazimuth mounts which can be guided to track the target's motion, unless a rotating erector prism is installed. Motor drives can also be added to an equatorial mount for automatic tracking of an object across the night sky.

Equatorial Mount

See also