Astr 103 ch. 6
Which of the following is NOT one of the three main categories of observation generally used by astronomers?
Filtering to look at just a SINGLE COLOR from an object
What is a CCD?
It is an ELECTRONIC DETECTOR that can be used IN PLACE OF PHOTOGRAPHIC FILM for making images
What do we mean by the DIFFRACTION LIMIT of a telescope?
It is the ANGULAR RESOLUTION the telescope COULD achieve if nothing besides the SIZE OF ITS LIGHT-COLLECTING AREA affected the quality of its images
What do astronomers mean by light pollution?
Light pollution is light from HUMAN SOURCES that makes it difficult to see the stars at night
Which of the following wavelength regions CAN be studied with telescopes on the ground?
Radio, Visible, and VERY LIMITED portions of the infrared and ultraviolet regions
Which of the following statements BEST describes the difference between a refracting telescope and a reflecting telescope?
a refracting telescope uses a TRANSPARENT GLASS LENSE to focus light while a reflecting telescope uses a MIRROR to focus light
What is the angular resolution of the human eye?
about 1 ARCMINUTE or 1/60 of a degree
What is the purpose of ADAPTIVE OPTICS?
it REDUCES BLURRING caused by atmospheric TURBULENCE for telescopes on the ground
What is the purpose of INTERFEROMETRY
it allows two or more SMALL TELESCOPES to achieve the angular resolution of a much larger telescope
Which of the following best describes what we mean by the FOCAL plane of a telescope? (review these terms in beg. of ch.)
it is the place where, if we MOUNTED FILM or an ELECTRONIC DETECTOR, we could get a clear (not blurry) IMAGE of an object viewed through the telescope
Which of the following statements best describes the two principle advantages of telescopes over eyes?
telescopes can collect far MORE LIGHT with far better ANGULAR RESOLUTION
What does ANGULAR RESOLUTION measure?
the angular size of the SMALLEST FEATURES a telescope can see
Which of the following effects is caused by atmospheric turbulence?
twinkling of stars