Telescope
A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation.Nowadays, the word "telescope" is defined as a wide range of instruments capable of detecting different regions of the electromagnetic spectrum, and in some cases other types of detectors.The word telescope 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.[8] The potential advantages of using parabolic mirrors—reduction of spherical aberration and no chromatic aberration—led to many proposed designs and several attempts to build reflecting telescopes.The largest reflecting telescopes currently have objectives larger than 10 meters (33 feet), and work is underway on several 30–40m designs.Even if a wavelength is observable from the ground, it might still be advantageous to place a telescope on a satellite due to issues such as clouds, astronomical seeing and light pollution.Telescopes such as TRACE and SOHO use special mirrors to reflect extreme ultraviolet, producing higher resolution and brighter images than are otherwise possible.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.Radio telescopes are also used to collect microwave radiation, which has the advantage of being able to pass through the atmosphere and interstellar gas and dust clouds.[24][25] An optical telescope gathers and focuses light mainly from the visible part of the electromagnetic spectrum.X-ray and Gamma-ray telescopes are usually installed on high-flying balloons[44][45] or Earth-orbiting satellites since the Earth's atmosphere is opaque to this part of the electromagnetic spectrum.
Telescope (disambiguation)reflecting telescopeMount Wilson ObservatoryEdwin Hubbleabsorptionreflectionelectromagnetic radiationoptical instrumentlensescurved mirrorsoptical telescopeelectromagnetic spectrumrefracting telescopesNetherlandsastronomyradio telescopesinfrared telescopesGiovanni DemisianiGalileo GalileiAccademia dei LinceiStarry MessengerAncient GreekHistory of the telescopeHans Lipperheyrefracting telescopeGalileoobjectiveparabolic mirrorsspherical aberrationchromatic aberrationreflecting telescopesIsaac NewtonNewtonian reflectorachromatic lensspeculum metalUrsa ObservatoryHelsinki, Finlandwavelengthsgamma-raysSpace telescopeastronomical seeingCrab NebulaJames Clerk Maxwell TelescopeSpitzer Space TelescopeHubble Space TelescopeWide Field Camera 3extreme ultravioletflying telescopeprofessional astronomersamateur astronomersobservatoryRadio telescopeRadio astronomySubmillimetre astronomyAtacama Large Millimeter Arraydirectionalradio antennaswavelengthfocal-plane arrayastronomical interferometersaperture synthesisvery-long-baseline interferometryaperture masking interferometrymicrowave radiationAllen Telescope ArrayArecibo ObservatoryInfrared telescopeInfrared astronomyVisible-light astronomyVery Large Telescopefocusesangular sizebrightnessmirrorstheodolitesspotting scopesmonocularsbinocularscamera lensesFresnel imagerFresnel lensastrographscomet seekerssolar telescopesUltraviolet astronomyX-ray telescopeX-ray astronomyHitomi telescopeconcentricX-raysX-ray opticsWolter telescopesheavy metalsdegreesparabolahyperbolaellipseHans WolterEinstein ObservatoryChandra X-ray ObservatoryNuSTARWolter telescopedeployableGamma-ray astronomyCompton Gamma Ray Observatorycoded aperturesatellitesEarth's atmosphereFermi Gamma-ray Space TelescopeImaging Atmospheric Cherenkov TelescopesH.E.S.S.VERITASLHAASOList of optical telescopesList of largest optical reflecting telescopesList of largest optical refracting telescopesList of largest optical telescopes historicallyList of radio telescopesList of solar telescopesList of space observatoriesList of telescope parts and constructionList of telescope typesAirmassAmateur telescope makingAngular resolutionBahtinov mask