Imagine that you are the head of a funding agency that can afford to build only one telescope. Which of the four proposed telescopes belowwould be best to support?OA. a radio telescope in orbit above the EarthB. A gamma ray telescope in orbit above the EarthOC. An x-ray telescope located on a mountain in PeruD.An ultraviolet telescope located in the Mojave desert

Because we use a telescope to observe an item from a great distance away, it must have at least two…

Answered: Imagine that you are the head of a…

The Solar System

9th Edition

ISBN:9781305804562

Author:Seeds

Publisher:Seeds

Chapter6: Light And Telescopes

Section: Chapter Questions

Problem 14P

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Similar questions

When astronomers discuss the apertures of their telescopes, they say bigger is better. Explain why.
The X-ray image in Figure UN 5-5 shows the remains of an exploded star. Explain why images recorded by telescopes in space are often displayed in representational (“false”) color rather than in the “colors” (wavelengths) received by the telescope.
Name the two spectral windows through which electromagnetic radiation easily reaches the surface of Earth and describe the largest-aperture telescope currently in use for each window.
Telescopes can now be operated remotely from a warm room, but until about 25 years ago, astronomers worked at the telescope to guide it so that it remained pointed in exactly the right place. In a large telescope, like the Palomar 200-inch telescope, astronomers sat in a cage at the top of the telescope, where the secondary mirror is located, as shown in Figure 6.6. Assume for the purpose of your calculation that the diameter of this cage was 40 inches. What fraction of the light is blocked? Figure 6.6 Focus Arrangements for Reflecting Telescopes. Reflecting telescopes have different options for where the light is brought to a focus. With prime focus, light is detected where it comes to a focus after reflecting from the primary mirror. With Newtonian focus, light is reflected by a small secondary mirror off to one side, where it can be detected (see also Figure 6.5). Most large professional telescopes have a Cassegrain focus in which light is reflected by the secondary mirror down through a hole in the primary mirror to an observing station below the telescope.
People are often bothered when they discover that reflecting telescopes have a second mirror in the middle to bring the light out to an accessible focus where big instruments can be mounted. “Don’t you lose light?” people ask. Well, yes, you do, but there is no better alternative. You can estimate how much light is lost by such an arrangement. The primary mirror (the one at the bottom in Figure 6.6) of the Gemini North telescope is 8 m in diameter. The secondary mirror at the top is about 1 m in diameter. Use the formula for the area of a circle to estimate what fraction of the light is blocked by the secondary mirror. Figure 6.6 Focus Arrangements for Reflecting Telescopes. Reflecting telescopes have different options for where the light is brought to a focus. With prime focus, light is detected where it comes to a focus after reflecting from the primary mirror. With Newtonian focus, light is reflected by a small secondary mirror off to one side, where it can be detected (see also Figure 6.5). Most large professional telescopes have a Cassegrain focus in which light is reflected by the secondary mirror down through a hole in the primary mirror to an observing station below the telescope.
What kind of visible-light and infrared telescopes on the ground are astronomers planning for the future? Why are they building them on the ground and not in space?
Why are the largest visible-light telescopes in the world made with mirrors rather than lenses?
List the largest-aperture single telescope currently in use in each of the following bands of the electromagnetic spectrum: radio, X-ray, gamma ray.

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