Exam 5: Telescopes: The Tools of Astronomy

The twinkling of starlight and the focusing of images by lenses are due to ________ of light.

Compared to optical telescopes,radio telescopes are built large because:

The ________ is a measure of the stability of the atmosphere,usually degraded by turbulent currents in the air.

Absorption of light passing through the glass is a bigger problem for Cassegrain reflectors than achromatic refractors.

Radio telescopes have poorer angular resolution than optical telescopes because radio waves have a much longer wavelength than optical waves.

The light gathering ability of a telescope is most dependent on the diameter of its primary objective.

Which of the following is currently supplying high resolution X-ray images from space?

Optical interferometry is more in use than radio interferometry.

In which part of the electromagnetic spectrum have astronomers been unable to get any information?

One reason for building telescopes on mountain tops is that they improve seeing by reducing the amount of air above the observer.

Describe at least three advantages of CCD imaging over visual or photographic work.

Diffraction is the tendency of light to:

The design of modern X-ray telescopes depends on:

Chromatic aberration affects refractor and reflector telescopes equally,unless they have very long focal lengths.

Which method of astronomical measurement is the precise measurement of brightness?

The process occurring when photons bounce off a polished surface is called:

Because of ________,images in small telescopes are more blurred than with larger objectives.

To reach the Cassegrain focus,a hole must be cut in the center of the primary mirror.

In addition to visible light,Hubble can do some work in the infrared and ultraviolet portions of the spectrum.

The tendency of a wave to bend as it passes from one transparent medium to another is called: