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Alt-Az Telescope By Troughton
An altazimuth mount or alt-azimuth mount is a simple two-coordinate axis, axis mount for supporting and Rotation around a fixed axis, rotating an instrument about two perpendicular axes – one vertical and the other horizontal. Rotation about the vertical axis varies the azimuth (compass bearing) of the pointing direction of the instrument. Rotation about the horizontal axis varies the altitude angle (angle of elevation) of the pointing direction. These mounts are used, for example, with Telescope mount, telescopes, cameras, antenna (radio), radio antennas, heliostat mirrors, solar tracker, solar panels, and weapon mount, guns and similar weapons. Several names are given to this kind of mount, including altitude-azimuth, azimuth-elevation and various abbreviations thereof. A gun turret is essentially an alt-azimuth mount for a gun, and a standard Tripod (photography), camera tripod is an alt-azimuth mount as well. Astronomical telescope altazimuth mounts When used as an astrono ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dobson Class
Dobson may refer to: People : ''For a listing of people with the surname "Dobson", see Dobson (surname).'' Places * Dobson High School in Arizona, US * Dobson, Mississippi, a ghost town in Rankin County, Mississippi, US * Dobson, North Carolina, US * Mount Dobson, New Zealand * Dobson, New Zealand Things * ''Dobson (Litigation Guardian of) v. Dobson'', [1999] 2 S.C.R. 753 (Supreme Court of Canada decision)) * Dobson Communications * Dobson ozone spectrophotometer * Dobson Pipe Organ Builders, a pipe organ manufacturer based in Iowa * Dobsonian telescope invented by amateur astronomer John Lowry Dobson * Dobson unit, a unit of measurement of atmospheric ozone named after British physicist Gordon M. B. Dobson {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equatorial Mount
An equatorial mount is a mount for instruments that compensates for Earth's rotation by having one rotational axis, called ''polar axis'', parallel to the Earth's axis of rotation. This type of mount is used for astronomical telescope mount, telescopes and cameras. The advantage of an equatorial mount lies in its ability to allow the instrument attached to it to stay fixed on any celestial object with diurnal motion by driving one axis at a constant speed. Such an arrangement is called a ''sidereal drive'' or ''clock drive''. Equatorial mounts achieve this by aligning their rotational axis with the Earth, a process known as ''polar alignment''. Astronomical telescope mounts In astronomical telescope mounts, the equatorial axis (the ''right ascension'') is paired with a second perpendicular coordinate axis, axis of motion (known as the ''declination''). The equatorial axis of the mount is often equipped with a motorized "''clock drive''", that rotates that axis one revolution e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Newtonian Reflectors
The Newtonian telescope, also called the Newtonian reflector or just a Newtonian, is a type of reflecting telescope invented by the English scientist Sir Isaac Newton, using a concave primary mirror and a flat diagonal secondary mirror. Newton's first reflecting telescope was completed in 1668 and is the earliest known functional reflecting telescope. The Newtonian telescope's simple design has made it very popular with amateur telescope makers. Description 
A Newtonian telescope is composed of a
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John Dobson (astronomer)
John Lowry Dobson (14 September 1915 – 15 January 2014) was an American amateur astronomer and is best known for the Dobsonian telescope, a portable, low-cost Newtonian reflector telescope. He was also known for his efforts to promote awareness of astronomy (and his unorthodox views of physical cosmology) through public lectures including his performances of " sidewalk astronomy". Dobson was also the co-founder of the amateur astronomical group, the San Francisco Sidewalk Astronomers. Biography Dobson was born to Methodist missionary parents in China, but moved with his family back to the U.S. as a young child. He was a “belligerent atheist” as a young man. After earning a master's in chemistry, he encountered a teacher of a Vedanta monastic order, which seeks to integrate Veda-based religious precepts with rational inquiry, and joined the order, where he served as a Vedantan monk for 23 years. After leaving the order (in part because the time he surreptitiously ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dobsonian Telescope
A Dobsonian telescope is an altazimuth mount, altazimuth-mounted Newtonian telescope design popularized by John Dobson (amateur astronomer), John Dobson in 1965 and credited with vastly increasing the size of telescopes available to amateur astronomy, amateur astronomers. Dobson's telescopes featured a simplified mechanical design that was easy to manufacture from readily available components to create a large, portable, low-cost telescope. The design is optimized for observing faint deep-sky objects such as nebulae and galaxies. This type of observation requires a large Objective (optics), objective diameter (i.e. Optical telescope#Light-gathering power, light-gathering power) of relatively short focal length and portability for travel to less light pollution, light-polluted locations. Dobsonians are intended to be what is commonly called a "light bucket". Operating at low magnification, the design therefore omits features found in other amateur telescopes such as Equatorial moun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Largest Optical Reflecting Telescopes
This list of the largest optical reflecting telescopes with Objective (optics), objective diameters of or greater is sorted by aperture, which is a measure of the light-gathering power and resolution of a reflecting telescope. The mirrors themselves can be larger than the aperture, and some telescopes may use aperture synthesis through interferometry. Telescopes designed to be used as optical astronomical interferometers such as the Keck I and II used together as the Keck Interferometer (up to 85 m) can reach higher resolutions, although at a narrower range of observations. When the two mirrors are on one mount, the combined mirror spacing of the Large Binocular Telescope (22.8 m) allows fuller use of the aperture synthesis. Largest does not always equate to being the best telescopes, and overall light gathering power of the optical system can be a poor measure of a telescope's performance. space observatory, Space-based telescopes, such as the Hubble Space Telescope, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zenith
The zenith (, ) is the imaginary point on the celestial sphere directly "above" a particular location. "Above" means in the vertical direction (Vertical and horizontal, plumb line) opposite to the gravity direction at that location (nadir). The zenith is the "highest" point on the celestial sphere. The direction opposite of the zenith is the nadir. Origin The word ''zenith'' derives from an inaccurate reading of the Arabic language, Arabic expression (), meaning "direction of the head" or "path above the head", by Medieval Latin scribes in the Middle Ages (during the 14th century), possibly through Old Spanish. It was reduced to ''samt'' ("direction") and miswritten as ''senit''/''cenit'', the ''m'' being misread as ''ni''. Through the Old French ''cenith'', ''zenith'' first appeared in the 17th century. Relevance and use The term ''zenith'' sometimes means the culmination, highest point, way, or level reached by a celestial body on its daily apparent path around a given poi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gimbal Lock
Gimbal lock is the loss of one degree of freedom (mechanics), degree of freedom in a multi-dimensional mechanism at certain alignments of the axes. In a three-dimensional three-gimbal mechanism, gimbal lock occurs when the axes of two of the gimbals are driven into a parallel configuration, "locking" the system into rotation in a degenerate two-dimensional space. The term can be misleading in the sense that none of the individual gimbals is actually restrained. All three gimbals can still rotate freely about their respective axes of suspension. Nevertheless, because of the parallel orientation of two of the gimbals' axes, there is no gimbal available to accommodate rotation about one axis, leaving the suspended object effectively locked (i.e. unable to rotate) around that axis. The problem can be generalized to other contexts, where a coordinate system loses definition of one of its variables at certain values of the other variables. Gimbals A gimbal is a ring that is suspen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Setting Circles
Setting circles are used on telescopes equipped with an equatorial mount to find celestial objects by their equatorial coordinates, often used in star charts and ephemerides. Description Setting circles consist of two graduated disks attached to the axes – right ascension (RA) and declination (DEC) – of an equatorial mount. The RA disk is graduated into hours, minutes, and seconds. The DEC disk is graduated into degrees, arcminutes, and arcseconds. Since the RA coordinates are fixed onto the celestial sphere, the RA disk is usually driven by a clock mechanism in sync with sidereal time. Locating an object on the celestial sphere using setting circles is similar to finding a location on a terrestrial map using latitude and longitude. Sometimes the RA setting circle has two scales on it: one for the Northern Hemisphere and one for the Southern. Application Research telescopes Historically setting circles have rivaled the telescopes optics as far as difficulty in constructio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Right Ascension
Right ascension (abbreviated RA; symbol ) is the angular distance of a particular point measured eastward along the celestial equator from the Sun at the equinox (celestial coordinates), March equinox to the (hour circle of the) point in question above the Earth. When paired with declination, these celestial coordinate system, astronomical coordinates specify the location of a point on the celestial sphere in the equatorial coordinate system. An old term, ''right ascension'' (), "''Ascensio recta'' Solis, stellæ, aut alterius cujusdam signi, est gradus æquatorus cum quo simul exoritur in sphæra recta"; roughly translated, "''Right ascension'' of the Sun, stars, or any other sign, is the degree of the equator that rises together in a right sphere" refers to the ''ascension'', or the point on the celestial equator that rises with any celestial object as seen from Earth's equator, where the celestial equator perpendicular, intersects the horizon at a right angle. It contrasts wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equatorial Platform
An equatorial platform or equatorial table is an equatorial telescope mount in the form of a specially designed platform that allows any device sitting on it to track astronomical objects in the sky on an equatorial axis. They are used to give equatorial tracking to any device sitting on them, from small cameras up to entire observatory buildings. They are often used with altazimuth mounted telescopes, such as the common Dobsonian telescope type, to overcome that type of mount's inability to track the night sky. With careful polar alignment sub-arc second precision CCD imaging is entirely possible. Roeser Observatory, Luxembourg (MPC observatory code 163) have contributed hundreds of astrometric measurements of Near Earth Asteroids to the Minor Planet Center using a home-built 20" Dobsonian telescope on an Osypowski equatorial platform. Types Many types of equatorial platform have been used over the years. The mid-1960s saw the introduction of the Russian AFU-75 satellite-tracking ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
