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30 November 2008 13:33
- a telescope design utilizing both mirrors and lenses, as opposed to reflectors - which only have mirrors, and refractors, which only have lenses
- popular catadioptric designs include the Schmidt-Cassegrain (SCT), the Maksutov-Cassegrain (MCT), and the Schmidt-Newtonian (SN), among others
- catadipotric is often shortened to "cat," - an astronomer who is called a "cat fancier" most likely doesn't know a tabby from a Russian Blue, but probably owns one or more catadioptric optical instruments
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in the image below, light entering the instrument from the left passes through a lens (the Schmidt corrector), reflects off the primary mirror at the far right, back to the secondary mirror on the left, and finally out the right hand-side through the visual back to an eyepiece or camera
25 November 2008 23:38
- a specialized type of photography targeting celestial bodies - including the stars, star trails, constellations, galaxies, nebulae, the moon, planets, asteroids, meteorites, comets, and even man-made satellites
- the first astrophotograph was a picture of the moon taken by John William Draper in 1840
- astrophotographs can be taken with film cameras, digital point and shoot cameras, digital SLRs, modified webcams, or dedicated astronomical CCDs
- cameras can be mounted on tripods for wide-field images of the stars (short exposures) or star trails (long-exposures), or mounted on sophisticated tracking mounts to counteract the rotation of the earth, allowing for multiple long exposures of the same spot in the sky
- images can be taken with camera lenses, or through telescopes
25 November 2008 23:26
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the (scientific) study of all aspects of celestial bodies, including their appearance, makeup and motions
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a sometimes maddening yet enjoyable hobby, undertaken by fools and masochists, that makes one painfully aware of light pollution, bad weather, and the cost of quality glass and workmanship
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(capitalized) a magazine published since August 1973 devoted to the hobby and science of astronomy
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-.com the website of the magazine Astronomy. Link: www.astronomy.com
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Orion Telescopes
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