The earliest existing record of a telescope was a patent submitted to the government in the Netherlands by Middelburg spectacle maker Hans Lippershey for a refracting telescope.
Galileo heard about it and, in , built his own version, and made his telescopic observations of celestial objects. The idea that the objective , or light-gathering element, could be a mirror instead of a lens was being investigated soon after the invention of the refracting telescope.
The invention of the achromatic lens in partially corrected color aberrations present in the simple lens and enabled the construction of shorter, more functional refracting telescopes. Reflecting telescopes, though not limited by the color problems seen in refractors, were hampered by the use of fast tarnishing speculum metal mirrors employed during the 18th and early 19th century—a problem alleviated by the introduction of silver coated glass mirrors in ,  and aluminized mirrors in The 20th century also saw the development of telescopes that worked in a wide range of wavelengths from radio to gamma-rays.
The first purpose built radio telescope went into operation in Since then, a large variety of complex astronomical instruments have been developed. The name "telescope" covers a wide range of instruments. Most detect electromagnetic radiation , but there are major differences in how astronomers must go about collecting light electromagnetic radiation in different frequency bands. As wavelengths become longer, it becomes easier to use antenna technology to interact with electromagnetic radiation although it is possible to make very tiny antenna.
The near-infrared can be collected much like visible light, however in the far-infrared and submillimetre range, telescopes can operate more like a radio telescope. Also using reflecting optics, the Hubble Space Telescope with Wide Field Camera 3 can observe in the frequency range from about 0. With photons of the shorter wavelengths, with the higher frequencies, glancing-incident optics, rather than fully reflecting optics are used.
A larger aperture does not just mean that more light is collected, it also enables a finer angular resolution. 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 professional astronomers or amateur astronomers. A vehicle or permanent campus containing one or more telescopes or other instruments is called an observatory. An optical telescope gathers and focuses light mainly from the visible part of the electromagnetic spectrum although some work in the infrared and ultraviolet. Optical telescopes are used for astronomy and in many non-astronomical instruments, including: theodolites including transits , spotting scopes , monoculars , binoculars , camera lenses , and spyglasses.
There are three main optical types:. A Fresnel Imager is a proposed ultra-lightweight design for a space telescope that uses a Fresnel lens to focus light. Beyond these basic optical types there are many sub-types of varying optical design classified by the task they perform such as astrographs , comet seekers and solar telescopes. Radio telescopes are directional radio antennas that typically employ a large dish to collect radio waves.
The dishes are sometimes constructed of a conductive wire mesh whose openings are smaller than the wavelength being observed. Unlike an optical telescope, which produces a magnified image of the patch of sky being observed, a traditional radio telescope dish contains a single receiver and records a single time-varying signal characteristic of the observed region; this signal may be sampled at various frequencies.
In some newer radio telescope designs, a single dish contains an array of several receivers; this is known as a focal-plane array. By collecting and correlating signals simultaneously received by several dishes, high-resolution images can be computed. Such multi-dish arrays are known as astronomical interferometers and the technique is called aperture synthesis.
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The 'virtual' apertures of these arrays are similar in size to the distance between the telescopes. Celestron Luminos 31 mm Eyepiece.
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Baader Tele Vue Explorer Scientific 68 Series 40mm Argon-Purged 2. Baader 2" SolarSpectrum 0.
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SBIG 65mm H-alpha 7nm. Baader Planetarium Narrowband 8. Astronomers have finally uncovered water vapor in the atmosphere of a super-Earth exoplanet orbiting within the habitable zone of its star.grupoavigase.com/includes/239/1561-fin-de-ano.php
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Read More. The Milky Way is blowing bubbles. Two giant radio bubbles, extending out from the galaxy for over 1, light years, were just discovered in X-ray data. Teeter Scopes are the best! Other than the marital discord from staying out too many nights, I couldn't be happier! It's such a beautiful scope! Engraved Brass Name Plate Name plate included on every Teeter's Telescope, signifying it as having been manufactured to our strict standards. Awaiting Nightfall Two Teeter's Telescopes await nightfall after being unloaded onto an observing field.
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Sharpened with Registax Assembled with Photoshop. Despite being big telescopes, they are still highly transportable. Work in Progress Various altitude bearings on the drying rack after staining and application of polyurethane clear gloss. Please see our July Press Release for more information, as well as the video below:. Originally built for a customer in California in October Originally built for a customer in New York State in May Originally sold to a customer in Missouri in October Originally completed for a customer in Pennsylvania in April Originally sold to a customer in Florida in August