Chap3 - Light_Telescopes

There are a wide range of wavelengths of

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Unformatted text preview: There are a wide range of wavelengths of electromagnetic waves. Only a very small range of wavelengths, 400nm to 700nm, is visible to humans What types of telescopes do you construct on the ground? you A. B. B. C. D. E. Optical Optical UV Radio X-ray A and C This replica of Newton’s reflecting telescope built in 1672. This reflecting telescope has a spherical primary mirror 3 cm (1.3 in.) in diameter. Its magnification was 40x. A Newtonian telescope Light-Gathering Power is proportional to the area of mirror. New technology has created charge-coupled devices (CCDs) that gather light more efficiently than photographic plates. This image of the Rosette Nebula, a region of star formation 5000 ly away in the constellation Monoceros (the Unicorn), was taken with this CCD. It shows the incredible detail that can be recorded by large telescopes and high-resolution CCDs. These three views of the same part of the sky, each taken with the same 4-m telescope, compare CCDs to photographic plates. (a) A negative print of a photographic image. (b) A negative CCD image. Notice that many faint stars and galaxies that are invisible in the ordinary photograph can be seen clearly in this CCD image. (c) This (positive) color view was produced by combining a series of CCD images taken through colored filters. A. Different colors of light are refracted differently and have different focal points. Thus, all the colors of the image will not be focused at once. This is called chromatic aberration. B. The weight of a large lens can cause the lens to sag and distort the image. C. Air bubbles in the glass cause unwanted refractions, distorting the image D. Glass is opaque to certain wavelengths of light, meaning Yerkes Observatory A. To make each 8.4-m primary mirror for the Large Binocular Telescope II on Mount Graham in Arizona, 40,000 pounds of glass are loaded into a rotating furnace and heated to 1450 K (2150°F). This image shows glass fragments loaded into the cylindrical furnace. B. Aft...
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This note was uploaded on 02/03/2014 for the course PHYS 1150 taught by Professor Satoshi during the Spring '08 term at Auburn University.

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