LECTURE 8

What are the three kinds of spectra?

• Continuous, emission, absorption

• Refraction, focusing, image formation

• Refracting, reflecting

• Imaging, spectroscopy, timing

What is another name for thermal emission?

• Blackbody emission

• Refraction

• Angular resolution

• Spectroscopy

What does refraction cause?

• Parallel light rays to converge to a focus

• Brightness, location, and structure of an astronomical object

• Splitting up of light into different wavelengths

• Bending of light when it passes from one substance into another

Where does light from different directions come into focus?

• Focal plane

• Diffraction limit

• Refracting telescope

• Reflecting telescope

How does the collecting area of a 10-meter telescope compare with that of a 2-meter telescope?

• It is 5 times greater

• It is 10 times greater

• It is 25 times greater

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What are the two basic designs of telescopes?

• Refracting telescope, reflecting telescope

• Imaging, spectroscopy, timing

• Brightness, location, and structure of an astronomical object

• Continuous, emission, absorption

What do astronomers do with telescopes?

• Taking pictures of the sky

• Breaking light into spectra

• Measuring how light output varies with time

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What does imaging tell us about an astronomical object?

• Brightness, location, and structure

• Chemical composition and other properties

• Details in a spectrum

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How does Earth's atmosphere affect ground-based observations?

• Calm, high, dark, dry

• Weather conditions and turbulence

• Seeing

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Why do we put telescopes in space?

• Wavelengths of light that do not penetrate Earth's atmosphere can be seen

• Images may be sharper, without moving air to blur them

• You are closer to the stars, for a better view

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