What is a telescope?
Optical telescope
"Observable world" describes what can be seen using a telescope, when viewing an object or range the observer may use many different techniques. Understanding what can be viewed and how to view it depends on the field of view. Viewing an object at a size that fits entirely in the field of view is measured using the two telescope properties—focal length and aperture, with the inclusion of an ocular eyepiece with suitable focal length (or diameter). Comparing the observable world and the angular diameter of an object shows how much of the object we see. However, the relationship with the optical system may not result in high surface brightness. Celestial objects are often dim because of their vast distance, and detail may be limited by diffraction or unsuitable optical properties.
Telescope Array Project
The Telescope Array has three fluorescence detector (FD) telescope stations. As in the previous Fly's Eye and High Resolution Fly's Eye (HiRes) experiments, these detectors work by measuring the air fluorescence light emitted by an extensive air shower. Each FD telescope consists of a primary mirror (made up of 18 smaller hexagonal mirror segments) and a camera. The cameras are made up of 256 PMTs (photomultiplier tubes) which are sensitive to the ultra violet light generated by a cosmic ray air shower.
Telescope
Telescopes may also be classified by location: ground telescope, [[space telescope]], or [[flying telescope]]. They may also be classified by whether they are operated by [[astronomer|professional astronomers]] or [[amateur astronomer]]s. A vehicle or permanent campus containing one or more telescopes or other instruments is called an [[observatory]].
Infinite-axis telescope
An example of this type of telescope was the late 17th century "Air" or "Aerial telescope", which was a very long focal length refracting telescope that did not use a tube. In these telescopes a hand held eyepiece and an objective mounted on a ball joint were connected by a string; the observer kept the string tight and moved the eyepiece to aim the telescope.
Telescope octopus
It is the only octopus to have tubular eyes, hence the reason it is commonly referred to as telescope octopus.
History of the telescope
Radio astronomy began in 1931 when Karl Jansky discovered that the Milky Way was a source of radio emission while doing research on terrestrial static with a direction antenna. Building on Jansky's work, Grote Reber built a more sophisticated purpose-built radio telescope in 1937, with a dish; using this, he discovered various unexplained radio sources in the sky. Interest in radio astronomy grew after the Second World War when much larger dishes were built including: the Jodrell bank telescope (1957), the Green Bank Telescope (1962), and the Effelsberg telescope (1971). The huge Arecibo telescope (1963) is so large that it is fixed into a natural depression in the ground; the central antenna can be steered to allow the telescope to study objects up to twenty degrees from the zenith. However, not every radio telescope is of the dish type. For example, the Mills Cross Telescope (1954) was an early example of an array which used two perpendicular lines of antennae in length to survey the sky.
Microscope
A microscope (from the , "mikrós", "small" and , "skopeîn", "to look" or "see") is an instrument used to see objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using such an instrument. Microscopic means invisible to the eye unless aided by a microscope.
Amateur telescope making
The telescopes amateur telescope makers build range from backyard variety to sophisticated instruments that make meaningful contributions to the field of astronomy. Instruments built by amateurs have been employed in planetary study, astrometry, photometry, comet and asteroid discovery to name just a few. Even the “hobbyist” end of the field can break down into several distinct categories such as: observing deep sky objects, observing the planets, solar observing, lunar observation, and astrophotography of all those classes of objects. Therefore, the design, size, and construction of the telescopes vary as well. Some amateur telescope makers build instruments that, while looking crude, are wholly suited to the purpose they are designed for. Others may strive for a more aesthetic look with high levels of mechanical “finish”. Since some amateur telescope makers do not have access to high-precision machining equipment, many elegant designs such as the Poncet Platform, Crayford focuser, and the Dobsonian telescope have evolved, which achieve functionality and stability without requiring precision machining.
Galileoscope
The Galileoscope is a small mass-produced refractor telescope, designed with the intention of increasing public interest in astronomy and science. It was developed for the International Year of Astronomy 2009. 
The small telescope has an aperture of 50 mm and a focal length of 500 mm, yielding a relatively long focal length of f/10.
It is meant to be an inexpensive means by which millions of people can view the same things seen by Galileo Galilei, such as the craters of Earth's Moon, four of Jupiter's moons, and the Pleiades.
Liverpool Telescope
The Liverpool Telescope is one of the primary players in the Heterogeneous Telescope Networks Consortium, a global collaboration between major research groups in the field of robotic telescopes which seeks a standard for communication between remote telescopes, telescope users, and other scientific resources.
Tower telescope
A Tower telescope is a telescope with a large refraction length at which the tube is installed inside a tower. Tower telescopes are mainly used for examinations of the sun.
Active optics
Most modern telescopes are reflectors, with the primary element being a very large mirror. Historically, primary mirrors were quite thick in order to maintain the correct surface figure in spite of forces tending to deform it, like wind and the mirror's own weight. This limited their maximum diameter to 5 or 6 metres (200 or 230 inches), such as Palomar Observatory's Hale telescope.
Amateur Telescope Making
Telescope making is a scientific hobby and it appeals doubtless because it exacts intelligence; requires patience and sometimes dogged persistence in order to whip the knotty but fascinating problems which arise; demands hard work -- is not dead easy; and compels the exercise of a fair amount of handiness -- enough to exclude the born bungler but no more than is possessed by the average man who can "tinker" his car or the household plumbing...The hobby also appeals because the worker derives something of a thrill while shaping the refined curve of the glass as he realizes that, with scarecly any special tools...he is able to work to within almost a millionth of an inch of absolute perfection.
William Herschel
The largest and most famous of Herschel's telescopes was a reflecting telescope with a primary mirror and a 40-foot (12 m) focal length. The 40-foot telescope was, at that time, the largest scientific instrument that had been built. It was hailed as a triumph of "human perseverance and zeal for the sublimest science".
List of solar telescopes
This list contains ground-based professional observatory telescopes at optical wavelengths in chronological order. Solar telescopes often have multiple focal lengths, and use a various combination of mirrors such as coelostats, lenses, and tubes for instruments including spectrographs, cameras, or coronagraphs. There are many types of instruments that have been designed to observe Earth's Sun, for example, in the 20th century solar towers were common.
Optical telescope
Optical telescopes have been used in astronomical research since the time of their invention in the early 17th century. Many types have been constructed over the years depending on the optical technology, such as refracting and reflecting, the nature of the light or object being imaged, and even where they are placed, such as space telescopes. Some are classified by the task they perform such as Solar telescopes.
Telescope
[[High-energy astronomy]] requires specialized telescopes to make observations since most of these particles go through most metals and glasses.
Telescope (goldfish)
The black telescope is a black colored variant of a telescope goldfish that has a characteristic pair of protruding eyes. Black telescopes are commonly known as Blackamoors, black moors or just moors, a reference to the black North African Muslim inhabitants of Al-Andalus.
Refracting telescope
A refracting telescope (also called a refractor) is a type of optical telescope that uses a lens as its objective to form an image (also referred to a dioptric telescope). The refracting telescope design was originally used in spy glasses and astronomical telescopes but is also used for long focus camera lenses. Although large refracting telescopes were very popular in the second half of the 19th century, for most research purposes the refracting telescope has been superseded by the reflecting telescope which allows larger apertures. A refractor's magnification is calculated by dividing the focal length of the objective lens by that of the eyepiece.
William Herschel Telescope
The telescope is housed in an onion-shaped steel dome with an internal diameter of , manufactured by Brittain Steel. The telescope mount is located on a cylindrical concrete pier so that the centre of rotation is above ground level, which lifts the telescope above ground-layer air turbulence for better seeing. A conventional up-down 6m-wide shutter with wind-blind, several large vents with extractor fans for thermal control, and a capacity crane (used for moving the primary mirror e.g. for aluminising) are all incorporated. The size and shape of the shutter allow observations down to 12° above the horizon, which corresponds to an airmass of 4.8. The total moving mass of the dome is , which is mounted on top of a three-storey cylindrical building. The dome was designed to minimise wind stresses and can support up to its own weight again in ice during inclement weather. The dome and telescope rest on separate sets of foundations (driven down into the volcanic basalt), to prevent vibrations caused by dome rotation or wind stresses on the building affecting the telescope pointing.
Eyepiece
An eyepiece, or ocular lens, is a type of lens that is attached to a variety of optical devices such as telescopes and microscopes. It is so named because it is usually the lens that is closest to the eye when someone looks through the device. The objective lens or mirror collects light and brings it to focus creating an image. The eyepiece is placed near the focal point of the objective to magnify this image. The amount of magnification depends on the focal length of the eyepiece.
Telescope
[[File:Telescope.jpg|thumb|160px|50 cm refracting telescope at [[Nice Observatory]].]]
Telescope
[[File:Heao b.jpg|thumb|200px|[[Einstein Observatory]] was a space-based focusing optical X-ray telescope from 1978. ]]
Telectroscope
The telectroscope (also referred to as 'electroscope') was the first conceptual model of a television or videophone system. The term was used in the 19th century to describe science-based systems of distant seeing.
Liquid mirror space telescope
A Space Telescope Mirror is a concept for a type of reflecting space telescope which uses a reflecting liquid such as mercury as its primary reflector.
Visible-light astronomy
Visible-light astronomy has existed as long as people have been looking up at the night sky, although it has since improved in its observational capabilities since the invention of the telescope, which is commonly credited to Hans Lippershey, a German-Dutch spectacle-maker, although Galileo played a large role in the development and creation of telescopes. Visible-light astronomy continues to advance in the modern day, with projects such as the James Webb Telescope being projected for launch in the next few years.
Track Imaging Cherenkov Experiment
The telescope is primarily a research and development tool for improving photomultiplier tube cameras and electronic systems for future gamma and cosmic ray telescopes. It is also used to study the energy and composition of cosmic rays in the TeV–PeV range, and the collaboration is currently conducting pioneering work in detecting direct Cherenkov signals from cosmic rays.
Very Large Telescope
The Very Large Telescope (VLT) is a telescope facility operated by the European Southern Observatory on Cerro Paranal in the Atacama Desert of northern Chile. The VLT consists of four individual telescopes, each with a primary mirror 8.2 m across, which are generally used separately but can be used together to achieve very high angular resolution. The four separate optical telescopes are known as "Antu", "Kueyen", "Melipal", and "Yepun", which are all words for astronomical objects in the Mapuche language. The telescopes form an array which is complemented by four movable Auxiliary Telescopes (ATs) of 1.8 m aperture.
Telephonoscope
A telephonoscope was an early concept of videophone and television, conceptualized in the late 1870s through the 1890s. It was mentioned in various early science fiction works such as "Le Vingtième siècle. La vie électrique" ("The Twentieth Century: The Electrical Life") and other works written by Albert Robida. It was also sketched in various cartoons by George du Maurier as a fictional invention by Thomas Edison including one made on December 9, 1878 in "Punch" magazine.
Telescope
An optical telescope gathers and [[Focus (optics)|focuses]] light mainly from the visible part of the [[electromagnetic spectrum]] (although some work in the [[infrared]] and [[ultraviolet]]). Optical telescopes increase the apparent [[angular size]] of distant objects as well as their apparent [[brightness]]. In order for the image to be observed, photographed, studied, and sent to a computer, telescopes work by employing one or more curved optical elements, usually made from [[glass]] [[Lens (optics)|lenses]] and/or [[mirror]]s, to gather light and other electromagnetic radiation to bring that light or radiation to a focal point. Optical telescopes are used for [[astronomy]] and in many non-astronomical instruments, including: "[[theodolite]]s" (including "transits"), "[[spotting scope]]s", "[[monocular]]s", "[[binoculars]]," "[[camera lens]]es", and "spyglasses". There are three main optical types:
Phase telescope
A phase telescope or Bertrand lens is an optical device used in aligning the various optical components of a light microscope. In particular it allows observation of the back focal plane of the objective lens and its conjugated focal planes. The phase telescope/Bertrand lens is inserted into the microscope in place of an eyepiece to move the intermediate image plane to a point where it can be observed.
Telescope
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. The two main types of tracking mount are:
Large Synoptic Survey Telescope
The Large-aperture Synoptic Survey Telescope (LSST) is a 6.5-m-class optical telescope designed to survey the visible sky every week down to a much fainter level than that reached by existing surveys. It will catalog 90 percent of the near-Earth objects larger than 300 m and assess the threat they pose to life on Earth. It will find some 10,000 primitive objects in the Kuiper Belt, which contains a fossil record of the formation of the solar system. It will also contribute to the study of the structure of the universe by observing thousands of supernovae, both nearby and at large redshift, and by measuring the distribution of dark matter through gravitational lensing. All the data will be available through the National Virtual Observatory (see below under “Small Initiatives”), providing access for astronomers and the public to very deep images of the changing night sky.
Early development was funded by a number of small grants, with major contributions in January 2008 by software billionaires Charles Simonyi and Bill Gates of $20 and $10 million respectively. $7.5 million was included in the U.S. President's FY2013 NSF budget request. The Department of Energy is funding construction of the digital camera component by the SLAC National Accelerator Laboratory, as part of its mission to understand dark energy.
NEOSTEL
The fly eye aspect of the telescope refers to the use of compound optics, as opposed to the single set of optics used in a conventional telescope. Historically, telescopes have been designed around a single human observer looking through an eye piece. As technology has developed astrographs have been used where either a photographic plate or CCD records the image, which a human observer can then view. With the human eye no longer directly observing the image there is no longer a restriction on a single viewing point. Further, as asteroid detection technology has developed, software has become fully automated and no longer requires a human observer to view the majority of images at all. Light enters the telescope through the aperture and is reflected off the primary mirror onto a beam splitter, which is a hexadecagonal pyramid in shape. The split beam then passes into 16 separate aspheric lenses and on to 16 corresponding CCD image sensors. NEOSTEL uses the 16 CCD cameras to view 45 square degrees of light entering the telescope aperture. The resolution is 1.5 arc seconds per pixel across the whole field of view.
Thomas Cooke (machinist)
Cooke studied optics and became interested in making telescopes, the first of which was a refracting telescope with the base of a tumbler shaped to form its lens. This led to his friends including John Phillips encouraging him to make telescopes and other optical devices commercially.
Sight (device)
A telescopic sight is an optical telescope equipped with some form of graphic image pattern reticle mounted in an optically appropriate position in the optical system to give an accurate aiming point. Telescopic sights are used on a wide range of devices including guns, surveying equipment, and even as sights on larger telescopes (called a finderscope).
Reflecting telescope
One design of telescope uses a rotating mirror consisting of a liquid metal in a tray which is spun at constant speed. As the tray spins the liquid forms a paraboloidal surface of essentially unlimited size. This allows for very big telescope mirrors (over 6 metres), but unfortunately they cannot be steered, as they always point vertically.
Optical telescope
An optical telescope is a telescope that gathers and focuses light, mainly from the visible part of the electromagnetic spectrum, to create a magnified image for direct view, or to make a photograph, or to collect data through electronic image sensors.
Major Atmospheric Cerenkov Experiment Telescope
The telescope is the second-largest gamma ray telescope in the world and will help the scientific community enhance its understanding in the fields of astrophysics, fundamental physics, and particle acceleration mechanisms. The largest telescope of the same class is the 28-metre-diameter High Energy Stereoscopic System (HESS) telescope being operated in Namibia.
Haploscope
A haploscope is an optical device for presenting one image to one eye and another image to the other eye. The word derives from two Greek roots: "haploieides", single and "skopeo", to view. The word is often used interchangeably with stereoscope, but it is more general than that. A stereoscope is a type of haploscope, but not vice versa. The word has more currency in the medical field than elsewhere, where it refers to instruments designed to test binocular vision. These instruments include Worth's amblyoscope and the synoptophore.
Petoscope
A Petoscope is an optoelectronic device for detecting small, distant objects such as flying aircraft. The design, as described in 1936, consisted of an instrument with two parallel light paths. In each path was a collimating objective lens, a screen marked with many small, alternating opaque and transparent squares in a chequerboard pattern, and a second concentrating lens focused on a photocell. The two screens were inverted with respect to each other. This caused a small object in the instrument's field of view to produce differing signals in the two photocells, while a large object affected both light paths equally. The difference between the two signals was amplified and used to raise an alarm. At the beginning of World War II, the device was adapted for use in proximity fuses for bombs.
Telescope (disambiguation)
Telescope(s) also may refer to:
Space telescope
A space telescope or space observatory is an instrument located in outer space to observe distant planets, galaxies and other astronomical objects. Space telescopes avoid many of the problems of ground-based observatories, such as light pollution and distortion of electromagnetic radiation (scintillation). In addition, ultraviolet frequencies, X-rays and gamma rays are blocked by the Earth's atmosphere, so they can only be observed from space.
South Pole Telescope
The telescope is a 10-meter (394 in) diameter off-axis Gregorian telescope in an altazimuth mount (at the poles, an altazimuth mount is effectively identical to an equatorial mount). It was designed to allow a large field of view (over 1 square degree) while minimizing systematic uncertainties from ground spill-over and scattering off the telescope optics. The surface of the telescope mirror is smooth down to roughly 25 micrometers (one thousandth of an inch), which allows sub-millimeter wavelength observations. A key advantage of the SPT observing strategy is that the entire telescope is scanned, so the beam does not move relative to the telescope mirrors. The fast scanning of the telescope and its large field of view makes SPT efficient at surveying large areas of sky, which is required to achieve the science goals of the SPT cluster survey and CMB polarization measurements.
Optical telescope
The telescope is more a discovery of optical craftsmen than an invention of a scientist. The lens and the properties of refracting and reflecting light had been known since antiquity and theory on how they worked were developed by ancient Greek philosophers, preserved and expanded on in the medieval Islamic world, and had reached a significantly advanced state by the time of the telescope's invention in early modern Europe. But the most significant step cited in the invention of the telescope was the development of lens manufacture for spectacles, first in Venice and Florence in the thirteenth century, and later in the spectacle making centers in both the Netherlands and Germany. It is in the Netherlands in 1608 where the first recorded optical telescopes (refracting telescopes) appeared. The invention is credited to the spectacle makers Hans Lippershey and Zacharias Janssen in Middelburg, and the instrument-maker and optician Jacob Metius of Alkmaar.
Observational astronomy
The key instrument of nearly all modern observational astronomy is the telescope. This serves the dual purposes of gathering more light so that very faint objects can be observed, and magnifying the image so that small and distant objects can be observed. Optical astronomy requires telescopes that use optical components of great precision. Typical requirements for grinding and polishing a curved mirror, for example, require the surface to be within a fraction of a wavelength of light of a particular conic shape. Many modern "telescopes" actually consist of arrays of telescopes working together to provide higher resolution through aperture synthesis.
Optics
Since crafting large lenses is much more difficult than crafting large mirrors, most modern telescopes are "reflecting telescopes", that is, telescopes that use a primary mirror rather than an objective lens. The same general optical considerations apply to reflecting telescopes that applied to refracting telescopes, namely, the larger the primary mirror, the more light collected, and the magnification is still equal to the focal length of the primary mirror divided by the focal length of the eyepiece. Professional telescopes generally do not have eyepieces and instead place an instrument (often a charge-coupled device) at the focal point instead.
Liverpool Telescope
The Liverpool Telescope (LT) is a fully robotic Ritchey–Chrétien telescope that observes autonomously; i.e., it operates without human intervention. Professional astronomers and other registered users submit observation specifications to be considered by the telescope's robotic control system (RCS) at any time of the day or night using an online GUI. Each night the RCS decides for itself what to observe next based on target visibility and weather conditions.
Telescope
Radio telescopes are [[Directional antenna|directional]] [[radio antennas]] used for [[radio astronomy]]. The dishes are sometimes constructed of a conductive wire mesh whose openings are smaller than the [[wavelength]] being observed. Multi-element [[Radio telescope]]s are constructed from pairs or larger groups of these dishes to synthesize large 'virtual' apertures that are similar in size to the separation between the telescopes; this process is known as [[aperture synthesis]]. As of 2005, the current record array size is many times the width of the [[Earth]]—utilizing space-based [[Very Long Baseline Interferometry]] (VLBI) telescopes such as the [[Japan]]ese [[HALCA]] (Highly Advanced Laboratory for Communications and Astronomy) VSOP (VLBI Space Observatory Program) satellite. Aperture synthesis is now also being applied to optical telescopes using [[Optical interferometry#Astronomical optical interferometry|optical interferometers]] (arrays of optical telescopes) and [[aperture masking interferometry]] at single reflecting telescopes. Radio telescopes are also used to collect [[microwave radiation]], which is used to collect radiation when any visible light is obstructed or faint, such as from [[quasar]]s. Some radio telescopes are used by programs such as [[Search for Extraterrestrial Intelligence|SETI]] and the [[Arecibo Observatory]] to search for extraterrestrial life.
Telescope
Telescopes are optical instruments that make distant objects appear magnified by using an arrangement of lenses or curved mirrors and lenses, or various devices used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. The first known practical telescopes were refracting telescopes invented in the Netherlands at the beginning of the 17th century, by using glass lenses. They found use in both terrestrial applications and astronomy.
Network telescope
A network telescope (also known as a darknet, Internet motion sensor or black hole) is an Internet system that allows one to observe different large-scale events taking place on the Internet. The basic idea is to observe traffic targeting the dark (unused) address-space of the network. Since all traffic to these addresses is suspicious, one can gain information about possible network attacks (random scanning worms, and DDoS backscatter) as well as other misconfigurations by observing it.
X-ray telescope
An X-ray telescope (XRT) is a telescope that is designed to observe remote objects in the X-ray spectrum. In order to get above the Earth's atmosphere, which is opaque to X-rays, X-ray telescopes must be mounted on high altitude rockets, balloons or artificial satellites.
List of solar telescopes
This is a list of solar telescopes built in various countries around the world. A solar telescope is a specialized telescope that is used to observe the Sun.
Telescope (goldfish)
Black telescopes are descendants of a type of wild carp known as Silver Prussian Carp or Gibel Carp, this fish is believed to originate from China in the 1400s. In the 1500s they were traded in Japan, and lastly, in the 1800s, they made their way to the USA. It is widely accepted they were a result of selective fish breeding by Chinese who first called them Dragon Fish or Dragon Eyes.
Optical Telescope Element
Optical Telescope Element (OTE) is a sub-section of the James Webb Space Telescope, a large infrared space telescope scheduled to be launched early 2021. The OTE consists of some major parts of the telescopes including the main mirror, the secondary mirrors, the framework and controls to support those mirrors, and various thermal and other systems to support the functioning of the telescope. The other two major sections of the JWST are the Integrated Science Instrument Module (holds instruments) and the Spacecraft Element (SE), which includes the Spacecraft Bus and Sunshield. The OTE collects the light and sends it to the science instruments in the ISIM. The OTE has been compared to being the "eye" of the telescope and the backplane of it to being the "spine".
Telescope
X-ray and Gamma-ray telescopes are usually on Earth-orbiting [[satellite]]s or high-flying balloons since the [[Earth's atmosphere]] is opaque to this part of the electromagnetic spectrum. However, high energy X-rays and gamma-rays do not form an image in the same way as telescopes at visible wavelengths. An example of this type of telescope is the [[Fermi Gamma-ray Space Telescope]].
Stratospheric Observatory for Infrared Astronomy
The telescope looks out of a large door in the port side of the fuselage near the airplane's tail, and initially carried nine instruments for infrared astronomy at wavelengths from 1–655 micrometres (μm) and high-speed optical astronomy at wavelengths from 0.3–1.1 μm. The main instruments are the FLITECAM, a near infrared camera covering 1–5 μm; FORCAST, covering the mid-infrared range of 5–40 μm, and HAWC, which spans the far infrared in the range 42–210 μm. The other four instruments include an optical photometer and infrared spectrometers with various spectral ranges. SOFIA’s telescope is by far the largest ever to be placed in an aircraft. For each mission one interchangeable science instrument will be attached to the telescope. Two groups of general purpose instruments are available. In addition, an investigator can also design and build a special purpose instrument. On April 17, 2012, two upgrades to HAWC were selected by NASA to increase the field of view with new transition edge sensor bolometer detector arrays and to add the capability of measuring the polarization of dust emission from celestial sources.
Stereo microscope
The stereo, stereoscopic or dissecting microscope is an optical microscope variant designed for low magnification observation of a sample, typically using light reflected from the surface of an object rather than transmitted through it. The instrument uses two separate optical paths with two objectives and eyepieces to provide slightly different viewing angles to the left and right eyes. This arrangement produces a three-dimensional visualization of the sample being examined. Stereomicroscopy overlaps macrophotography for recording and examining solid samples with complex surface topography, where a three-dimensional view is needed for analyzing the detail.
Infrared telescope
An infrared telescope is a telescope that uses infrared light to detect celestial bodies.
Infrared light is one of several types of radiation present in the electromagnetic spectrum.
Robotic telescope
A robotic telescope is an astronomical telescope and detector system that makes observations without the intervention of a human. In astronomical disciplines, a telescope qualifies as robotic if it makes those observations without being operated by a human, even if a human has to initiate the observations at the beginning of the night, or end them in the morning. It may have software agent(s) using Artificial Intelligence that assist in various ways such as automatic scheduling. A robotic telescope is distinct from a remote telescope, though an instrument can be both robotic and remote.
Optical telescope
Field of view is the extent of the observable world seen at any given moment, through an instrument (e.g., telescope or binoculars), or by naked eye. There are various expressions of field of view, being a specification of an eyepiece or a characteristic determined from and eyepiece and telescope combination. A physical limit derives from the combination where the FOV cannot be viewed larger than a defined maximum, due to diffraction of the optics.
Reticle
A reticle, or reticule (), also known as a graticule (), is a pattern of fine lines or markings built into the eyepiece of a sighting device, such as a telescopic sight in a telescope, a microscope, or the screen of an oscilloscope, to provide measurement references during visual examination. Today, engraved lines or embedded fibers may be replaced by a computer-generated image superimposed on a screen or eyepiece. Both terms may be used to describe any set of lines used for optical measurement, but in modern use "reticle" is most commonly used for gunsights and such, while "graticule" is more widely used for the oscilloscope display, microscope slides, and similar roles.
Observatory Naef Épendes
The invention of the telescope in 1608 and the subsequent improvements in optics led to the revolutionary progress of the 17th and 18th centuries. We call this type of telescope a refractor because it deviates the light coming from an object in such a way that its image is reversed ; observation is done through an eyepiece at the end of the tube, which allows magnification of the image. Bequeathed by Mr. Robert A. Naef, the observatory's precious telescope is a Reinfelder & Hertel with a diameter of 162.5 mm and a focal distance of 1435 mm - this allows a magnification of X150.
Solar telescope
A solar telescope is a special purpose telescope used to observe the Sun. Solar telescopes usually detect light with wavelengths in, or not far outside, the visible spectrum. Obsolete names for Sun telescopes include heliograph and photoheliograph.
Cystoscopy
The urethra is the tube that carries urine from the bladder to the outside of the body. 
The cystoscope has lenses like a telescope or microscope. These lenses let the physician focus on the inner surfaces of the urinary tract. Some cystoscopes use optical fibres (flexible glass fibres) that carry an image from the tip of the instrument to a viewing piece at the other end. Cystoscopes range from pediatric to adult and from the thickness of a pencil up to approximately 9 mm and have a light at the tip. Many cystoscopes have extra tubes to guide other instruments for surgical procedures to treat urinary problems.
Zenith
A zenith telescope is a type of telescope designed to point straight up at or near the zenith, and used for precision measurement of star positions, to simplify telescope construction, or both. The NASA Orbital Debris Observatory and the Large Zenith Telescope are both zenith telescopes since the use of liquid mirrors meant these telescopes could only point straight up.
Telescope
*Links to categories.
[[Category:Telescopes| ]]
[[Category:Astronomical imaging]]
[[Category:Astronomical instruments]]
[[Category:Science and technology in the Dutch Republic]]
[[Category:Dutch inventions]]
[[Category:17th-century introductions]]
Telescope
Beyond these basic optical types there are many sub-types of varying optical design classified by the task they perform such as [[astrograph]]s, [[comet seeker]]s and [[solar telescope]]s.
[[File:USA.NM.VeryLargeArray.02.jpg|thumb|200px|The [[Very Large Array]] at Socorro, New Mexico, United States.]]
Telescope
The reflecting telescope, which uses mirrors to collect and focus light, was invented within a few decades of the first refracting telescope. In the 20th century, many new types of telescopes were invented, including radio telescopes in the 1930s and infrared telescopes in the 1960s. The word "telescope" now refers to a wide range of instruments capable of detecting different regions of the electromagnetic spectrum, and in some cases other types of detectors.
Telescope
The word "telescope" (from the Ancient Greek τῆλε, "tele" "far" and σκοπεῖν, "skopein" "to look or see"; τηλεσκόπος, "teleskopos" "far-seeing") was coined in 1611 by the Greek mathematician Giovanni Demisiani for one of Galileo Galilei's instruments presented at a banquet at the Accademia dei Lincei. In the "Starry Messenger", Galileo had used the term "perspicillum".
Fremont Peak Observatory
The facility uses a telescope called Challenger. This is a 30-inch diameter telescope, "one of the largest telescopes available for public use" on an "English cross-axis equatorial mount" with a f/4.8 Newtonian lens. The telescope was made by Kevin and Denni Medlock from the Eastbay Astronomical Society, "in the early 1980s. First light was 1986." They "ground the mirror and built the scope in their garage". The scope weighs one ton and sits in a room the size of a classroom, according to intern, Edwin Levin, the "'mirror itself weighs 250 pounds. It's bolted into solid concrete, straight through the mountain, down to bedrock. A little motor, which matches the speed of the earth's rotation, keeps the telescope centered on the object we’re looking at.'"
List of space telescopes
As the atmosphere is transparent for radio waves, radio telescopes in space are of most use for Very Long Baseline Interferometry; doing simultaneous observations of a source with both a satellite and a ground-based telescope and by correlating their signals to simulate a radio telescope the size of the separation between the two telescopes. Observations can be of supernova remnants, masers, gravitational lenses, starburst galaxies, and many other things.
Telescopic sight
A telescopic sight, commonly called a scope, is an optical sighting device that is based on a refracting telescope. They are equipped with some form of graphic image pattern (a reticle) mounted in an optically appropriate position in their optical system to give an accurate aiming point. Telescopic sights are used with all types of systems that require accurate aiming but are most commonly found on firearms, particularly rifles. Other types of sights are iron sights, reflector (reflex) sights, and laser sights. The optical components may be combined with optoelectronics to form a night scope.
Robert E. Cox
It is generally conceded that anyone who mounts a mirror or lens as a telescope for viewing celestial objects has become a telescope "nut" regardless of how the optics were obtained. There is only one important requirement - that the optics be of first quality, capable of giving satisfactory views of the moon, the sun, double stars, cluster, nebulae, and the planets.
Advanced Technology Large-Aperture Space Telescope
The Advanced Technology Large-Aperture Space Telescope (ATLAST) is an 8– to 16.8–meter UV-optical-NIR space telescope proposed by the Space Telescope Science Institute (STScI), the science operations center for the Hubble Space Telescope (HST). If launched, ATLAST would be a replacement and successor for the HST, with the ability to obtain spectroscopic and imaging observations of astronomical objects in the ultraviolet, optical, and infrared wavelengths, but with substantially better resolution than either HST or the planned James Webb Space Telescope (JWST). Like JWST, ATLAST would be launched to the Sun-Earth Lagrange point.
Space telescope
Space telescopes are distinct from other imaging satellites pointed toward Earth for purposes of espionage, weather analysis and other types of information gathering.
Zenith telescope
A zenith telescope is a type of telescope that is designed to point straight up at or near the zenith. They are used for precision measurement of star positions, to simplify telescope construction, or both.
Finderscope
A finderscope is an aiming device used in astronomy, typically a small auxiliary telescope mounted on the main astronomical telescope along the same line of sight. The finderscope usually has a smaller magnification than the main telescope, providing a much larger field of view, useful for manually aiming (also called "slewing") a telescope and locating a desired astronomical object. Some finderscopes have crosshairs to aid in accurately pointing the telescope system at a target.
Cheiroscope
A cheiroscope (also: "chiroscope") is an optical device consisting of a viewing instrument equipped with a drawing pad, with the viewing instrument set up as a haploscope that blends a left and/or right image into view over the drawing.
Infinite-axis telescope
An infinite-axis telescope is a telescope that can move freely in all directions. Such telescopes can be mechanically simple hand-guided versions with the mounting serving only to carry the weight of the telescope although there are equatorial versions.
Tasco
Tasco (also known as Tasco Worldwide) is a major distributor of consumer telescopes worldwide. Tasco mainly makes telescopes for amateur astronomers but has expanded into other optical products such as spotting scopes, microscopes, binoculars, and telescopic sights and other rifle accessories. Tasco sells via specialty outlets, catalogues, and online retailers.
3.67 m Advanced Electro Optical System Telescope
The 3.67-meter telescope, known as the Advanced Electro-Optical System (AEOS), owned by the Department of Defense, is the United States' largest optical telescope designed for tracking satellites. The 75-ton AEOS telescope points and tracks very accurately, yet is fast enough to track both low-Earth satellites and ballistic missiles. It can slew at nearly 20 degrees per second. It is an f/200 and has an extremely narrow field of view. AEOS can be used simultaneously by many groups or institutions because its light can be channeled through a series of mirrors to seven independent coudé rooms below the telescope. Employing sophisticated sensors that include an adaptive optics system, radiometer, spectrograph, and long-wave infrared imager, the telescope tracks man-made objects in deep space and performs space object identification data collection.
Asteroid impact prediction
The Near Earth Object Survery TELescope (NEOSTEL) is an ESA funded project, starting with an initial prototype currently under construction. The telescope is of a new "fly-eye" design that combines a single reflector with multiple sets of optics and CCDs, giving a very wide field of view (around 45 square degrees). When complete it will have the widest field of view of any telescope and will be able to survey the majority of the visible sky in a single night. If the initial prototype is successful, three more telescopes are planned for installation around the globe. Because of the novel design, the size of the primary mirror is not directly comparable to more conventional telescopes, but is equivalent to a conventional 1 metre telescope.
Timeline of United States inventions (1890–1945)
A radio telescope is a form of directional radio antenna used in radio astronomy. They differ from optical telescopes in that they operate in the radio frequency portion of the electromagnetic spectrum where they can detect and collect data on radio sources. Radio telescopes are typically large parabolic or dish antenna used singularly or in an array. Karl Guthe Jansky started the field of radio astronomy serendipitous in 1932 when his directional antenna found radio static that he later identified as coming from the Milky Way.
Hobby–Eberly Telescope
The Hobby–Eberly Telescope (HET) is a 10-meter (30-foot) aperture telescope located at the McDonald Observatory. It is one of the largest optical telescopes in the world and combines a number of features that differentiate it from most telescope designs, resulting in greatly lowered construction costs. For instance, the primary mirror is constructed from 91 hexagonal segments, which is less expensive than manufacturing a single large primary. Furthermore, the telescope's main mirror is fixed at a 55° angle and can rotate around its base. A target is tracked by moving the instruments at the focus of the telescope; this provides access to about 70–81% of the sky at its location and allows a single target to be tracked for up to two hours. The telescope is named for former Texas Lieutenant-Governor Bill Hobby and for Robert E. Eberly, a Penn State benefactor.
Borescope
A borescope (occasionally called a boroscope, though this spelling is nonstandard) is an optical device consisting of a rigid or flexible tube with an eyepiece or display on one end, an objective lens or camera on the other linked together by an optical or electrical system in between. The optical system in some instances is surrounded by optical fibers used for illumination of the remote object. An internal image of the illuminated object is formed by the objective lens and magnified by the eyepiece which presents it to the viewer's eye.
Visible-light astronomy
Hans Lippershey, a German-Dutch spectacle-maker, is commonly credited as being the first to invent the telescope. Lippershey is the first recorded person to apply for a patent for a telescope, however it is unclear if Lippershey was the first to build a telescope. Based only on uncertain descriptions of the telescope which Lippershey tried to obtain a patent for, Galileo made a telescope with about 3x magnification in the following year. Galileo later made improved versions with up to 30x magnification. With a Galilean telescope the observer could see magnified, upright images on the earth—it was what is commonly known as a terrestrial telescope or a spyglass. Galileo could also use it to observe the sky, and for a time was one of those who could construct telescopes good enough for that purpose. On 25 August 1609, Galileo demonstrated one of his early telescopes, with a magnification of up to 8 or 9, to Venetian lawmakers. Galileo's telescopes were also a profitable sideline; selling them to merchants who found them useful both at sea and as items of trade. He published his initial telescopic astronomical observations in March 1610 in a brief treatise entitled "Sidereus Nuncius" ("Starry Messenger").
Visual prosthesis
Created by VisionCare Ophthalmic Technologies in conjunction with the CentraSight Treatment Program, the telescope is about the size of a pea and is implanted behind the iris of one eye. Images are projected onto healthy areas of the central retina, outside the degenerated macula, and is enlarged to reduce the effect the blind spot has on central vision. 2.2x or 2.7x magnification strengths make it possible to see or discern the central vision object of interest while the other eye is used for peripheral vision because the eye that has the implant will have limited peripheral vision as a side effect. Unlike a telescope which would be hand-held, the implant moves with the eye which is the main advantage. Patients using the device may however still need glasses for optimal vision and for close work. Before surgery, patients should first try out a hand-held telescope to see if they would benefit from image enlargement. One of the main drawbacks is that it cannot be used for patients who have had cataract surgery as the intraocular lens would obstruct insertion of the telescope. It also requires a large incision in the cornea to insert.
Optical telescope
Relatively cheap, mass-produced ~2 meter telescopes have recently been developed and have made a significant impact on astronomy research. These allow many astronomical targets to be monitored continuously, and for large areas of sky to be surveyed. Many are robotic telescopes, computer controlled over the internet (see "e.g." the Liverpool Telescope and the Faulkes Telescope North and South), allowing automated follow-up of astronomical events.
Telescope
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Telescope
[[File:Kepler CCD matrix.jpg|thumb|Modern telescopes typically use [[Charge-coupled device|CCDs]] instead of film for recording images. This is the sensor array in the [[Kepler (spacecraft)|Kepler spacecraft]].]]
List of astronomical observatories
Many modern telescopes and observatories are located in space to observe astronomical objects in wavelengths of the electromagnetic spectrum that cannot penetrate the Earth's atmosphere (such as ultraviolet radiation, X-rays, and gamma rays) and are thus impossible to observe using ground-based telescopes.
Being above the atmosphere, these space observatories can also avoid the effects of atmospheric turbulence that plague ground based telescopes, although new generations of adaptive optics telescopes have since then dramatically improved the situation on the ground. The space high vacuum environment also frees the detectors from the ancestral diurnal cycle due to the atmospheric blue light background of the sky, thereby increasing significantly the observation time.
Stereoscope
A simple stereoscope is limited in the size of the image that may be used. A more complex stereoscope uses a pair of horizontal periscope-like devices, allowing the use of larger images that can present more detailed information in a wider field of view. The stereoscope is essentially an instrument in which two photographs of the same object, taken from slightly different angles, are simultaneously presented, one to each eye. This recreates the way which in natural vision, each eye is seeing the object from a slightly different angle, since they are separated by several inches, which is what gives humans natural depth perception. Each picture is focused by a separate lens, and by showing each eye a photograph taken several inches apart from each other and focused on the same point, it recreates the natural effect of seeing things in three dimensions.
Radio telescope
One of the most notable developments came in 1946 with the introduction of the technique called astronomical interferometry, which means combining the signals from multiple antennas so that they simulate a larger antenna, in order to achieve greater resolution. Astronomical radio interferometers usually consist either of arrays of parabolic dishes (e.g., the One-Mile Telescope), arrays of one-dimensional antennas (e.g., the Molonglo Observatory Synthesis Telescope) or two-dimensional arrays of omnidirectional dipoles (e.g., Tony Hewish's Pulsar Array). All of the telescopes in the array are widely separated and are usually connected using coaxial cable, waveguide, optical fiber, or other type of transmission line. Recent advances in the stability of electronic oscillators also now permit interferometry to be carried out by independent recording of the signals at the various antennas, and then later correlating the recordings at some central processing facility. This process is known as Very Long Baseline Interferometry (VLBI). Interferometry does increase the total signal collected, but its primary purpose is to vastly increase the resolution through a process called Aperture synthesis. This technique works by superposing (interfering) the signal waves from the different telescopes on the principle that waves that coincide with the same phase will add to each other while two waves that have opposite phases will cancel each other out. This creates a combined telescope that is equivalent in resolution (though not in sensitivity) to a single antenna whose diameter is equal to the spacing of the antennas furthest apart in the array.
Copyscope
A copyscope is type of refracting telescope that can be made by hand rather than bought in which the objective lens comes from an old photocopy machine, hence the origin of the name. The lenses usually come from defective or old photocopiers, allowing for the objective to be obtained for free or at a low cost. They are usually modest aperture lenses, ranging from 50mm to 60mm, of short focal length, good for use in a portable, wide-field telescope, but unsuitable for higher magnifications. Given the use of good components, however, a copyscope can become a rich-field instrument capable of reaching many extended objects and even star fields.
Kinescope
Kinescope , shortened to kine , also known as telerecording in Britain, is a recording of a television program on motion picture film, directly through a lens focused on the screen of a video monitor. The process was pioneered during the 1940s for the preservation, re-broadcasting and sale of television programmes before the use of commercial broadcast-quality videotape became prevalent for these purposes.
Telescoping stock
A telescoping stock (alternatively collapsing stock) is a stock on a firearm that telescopes or folds in on itself in order to become more compact. Telescoping stocks are useful for storing a rifle or weapon in a space that it would not normally fit in. The user can either fold in the stock to make the weapon easier to handle, or extend it for better accuracy. Finally, some telescoping stocks, such as those on the M4 carbine, have more than one setting, allowing the stock to be adjusted for different users. In the context of the U.S. Federal Assault Weapons Ban, the National Rifle Association deemed telescoping stocks a "cosmetic feature".
Gregorian telescope
The Gregorian design solved the problem of viewing the image in a reflector by allowing the observer to stand behind the primary mirror. This design of telescope renders an upright image, making it useful for terrestrial observations. It also works as a telephoto in that the tube is much shorter than the system's actual focal length.
Balloon-borne telescope
A balloon-borne telescope is a sub-orbital astronomical telescope that is suspended below one or more stratospheric balloons, allowing it to be lifted above the lower, dense part of the Earth's atmosphere. This has the advantage of improving the resolution limit of the telescope at a much lower cost than for a space telescope. It also allows observation of frequency bands that are blocked by the atmosphere.
List of largest optical reflecting telescopes
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-based telescopes, such as the Hubble Space Telescope, take advantage of being above the Earth's atmosphere to reach higher resolution and greater light gathering through longer exposure time. Location in the northern or southern hemisphere of the Earth can also limit what part of the sky can be observed.
Telescope
[[X-ray]] telescopes can use [[X-ray optics]], such as a [[Wolter telescope]]s composed of ring-shaped 'glancing' [[mirror]]s made of [[heavy metals]] that are able to reflect the rays just a few [[degree (angle)|degrees]]. The mirrors are usually a section of a rotated [[parabola]] and a [[hyperbola]], or [[ellipse]]. In 1952, [[Hans Wolter]] outlined 3 ways a telescope could be built using only this kind of mirror. Examples of an observatory using this type of telescope are the [[Einstein Observatory]], [[ROSAT]], and the [[Chandra X-Ray Observatory]]. By 2010, Wolter focusing X-ray telescopes are possible up to 79 keV.