Mounts(Engelstalig)

[Ton Dix]

A telescope mount is a mechanical structure which supports a telescope. Telescope mounts are designed to support the mass of the telescope and allow for accurate pointing of the instrument. Many sorts of mounts have been developed over the years, with the majority of effort being put into systems that can track the motion of the stars as the Earth rotates with a single motion.

Altazimuth mount

An Altazimuth or alt-azimuth mount is a simple two-axis mount for supporting and rotating an instrument about two mutually perpendicular axes; a vertical (altitude) axis, and a horizontal (azimuth) axis.
One limitation of this mount is that the telescope's field-of-view rotates at varying speed as the telescope tracks, whilst the telescope body does not, thus causing problems with astro-photography, for example. This type of mount is used in practically all modern big telescopes, and has also become popular with inexpensive commercial and hobby constructions.

Equatorial mount

The introduction of the equatorial mount displaced most alt-az systems for many serious users for several centuries. By tilting the horizontal base of an alt-az system up until it is parallel to Earth's equatorial plane, the azimuth rotation then swings the telescope in an arc that follows the stars as they move across the sky due to Earth's rotation. By attaching a simple clockwork mechanism to this axis, the equatorial system makes long observation easy. Also the telescope's field-of-view does not rotate, which all combined make these simpler tools to use in e.g. astro-photography.

Equatorial mounts come in different shape, most common forms include German Equatorial Mount (GEM in short), equatorial fork mount, and equatorial platform.

See also: Mounts