Horizontal Telescope

Telescope, Horizontal


a telescope whose optical axis is stationary and fixed on the plane of the horizon (usually in a north-south direction).

The horizontal telescope is used primarily for observing the sun and moon and, less often, the planets and stars. In a horizontal telescope a system of plane mirrors, including a mobile mirror moved by a clockwork mechanism (usually electric) reflects the light of a moving heavenly body constantly along the optical axis of the stationary telescope. The objective of a horizontal telescope, which can be a mirror (concave parabolic and, with a small aperture ratio, spherical) as well as a lens, projects the image of a heavenly body on a photoreceptive instrument, such as a spectrograph, a spec-trohelioscope, a spectroheliograph, or a magnetograph.

References in periodicals archive ?
Caption: SUN SPOTTING The Snow horizontal telescope (coelostat) was a gift to Yerkes Observatory from Helen E.
To overcome these problems the group decided to build a novel type of instrument, in which a large movable flat mirror would direct starlight into a stationary, horizontal telescope. The mirroring device, called a single-mirror siderostat, had been invented in 1862 by the French physicist Leon Foucault.

Full browser ?