 An Equatorial Mount for a telescope. 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. Equatorial mounts are often equipped with a motor drive for automatic tracking of objects across the night sky. They may also be equipped with setting circles to allow for the location of objects by their celestial coordinates. Download high resolution version (480x640, 42 KB)An Equatorial mount. ...
Download high resolution version (480x640, 42 KB)An Equatorial mount. ...
Look up Mount in Wiktionary, the free dictionary. ...
50 cm refracting telescope at Nice Observatory. ...
A camera is a device used to take pictures (usually photographs), either singly or in sequence, with or without sound recording, such as with video cameras. ...
Perpendicular is a geometric term that may be used as a noun or adjective. ...
A coordinate axis is one of a set of vectors that defines a coordinate system. ...
Right ascension (RA; symbol α: Greek letter alpha) is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. ...
In astronomy, declination (dec) is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. ...
For other uses of the word pole, see Pole (disambiguation). ...
Latitude, usually denoted symbolically by the Greek letter φ, gives the location of a place on Earth north or south of the Equator. ...
Setting Circles are used on telescopes to find astronomical objects in the sky by their coordinates as listed in a star chart or ephemeris using the celestial coordinate system. ...
In astronomy, a celestial coordinate system is a coordinate system for mapping positions in the sky. ...
The advantage of an equatorial mount lies in its ability to track an object moving across the sky using constant speed movement around only one axis, unlike an altazimuth mount, which requires variable speed motion around both axes to track the diurnal motion. Also, for astrophotography, the image does not rotate in the focal plane, as occurs with altazimuth mounts when they are guided to track the target's motion, unless a rotating erector prism is installed (or other field-derotator). An Altazimuth or alt-azimuth mount is a simple mount used for moving a telescope or camera along two perpendicular axes of motion. ...
Diurnal motion is an astronomical term referring to the apparent daily motion of stars in orbit around the Earth, caused by the Earths rotation around its axis. ...
Astrophotography is a specialised type of photography that entails making photographs of astronomical objects in the night sky such as planets, stars, and deep sky objects such as star clusters and galaxies. ...
The focal plane of a lens is a plane that is perpendicular to the axis of the lens and passes through its focus. ...
English mount
In the English mount the system is like big +-sign. The right ascension axis is supported at both ends, and the declination axis is attached to it at approximately mid point.
The telescope is placed on other end of the declination axis, and suitable counterweight on other end of it.
German mount In the Germant mount the primary structure is a big T-shape, where "vertical" bar is the right ascension axis, and "horisontal" is the declination axis. The right ascension axis has bearings below the T-joint, that is, it is not supported above the declination axis.
The telescope is placed on other end of the declination axis, and suitable counterweight on other end of it.
This is most common type of telescope mounts, and many amateur telescopes from 60mm (2.4") refractors to 14" Schmidt-Cassegrain telescopes are mounted on this mount. In astronomy, the telescope mount is an important part of the overall design of an operational telescope. ...
Schmidt-Cassegrain The Schmidt-Cassegrain, invented by Bernhard Schmidt, is similar to the Cassegrain. ...
English fork In English Fork there is a frame that has right ascension axis bearings at the top and the bottom ends, and the declination axis is at its approximate midpoint. The telescope is fitted entirely inside the fork (or not, as is the case with Mt. Wilson 2.5m reflector) and there are no counterweights like german mount has. The Mount Wilson Observatory (MWO) is an astronomical observatory in Los Angeles County, California. ...
Original english fork has the disadvantage of being blocked by the frame from pointing to near north (or south) pole of the sky. For example the Hale telescope is an english fork even though the north end has been changed into huge horse shoe so that it can point to north pole. The Hale Telescope is the largest telescope at the Palomar Observatory. ...
Open fork Most modern mass-produced catadioptic (200mm or larger diameter) reflecting telescopes tend to be of this type. The mount resembles an Altazimuth mount, but with the azimuth axis is tilted and lined up to match earth rotation axis with a piece of hardware usually called a "wedge." An Altazimuth or alt-azimuth mount is a simple mount used for moving a telescope or camera along two perpendicular axes of motion. ...
Many mid-size professional telescopes also have equatorial forks, these are usually in range of 0.5-2.0 meter diameter.
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