astronomy chapter 5

reflecting telescopes?worlds largest, mostly used by astronomers today and the hubble space telescope
refracting telescope?incoming light passes through glass, largest 1 meter in diameter, top heavy and galileos telescope
The thickest lenses deflect and bend light?the most
The main reason that most professional research telescopes are reflectors is that?large mirrors are easier to build than large lenses
What is the primary purpose of an astronomical telescope?to collect a lot of light and bring it to a focus.
The process occurring when photons bounce off a polished surface is called:reflection
Which design is subject to chromatic aberration?refractor
The tendency of a wave to bend as it passes from one transparent medium to
another is called:
refraction
What problem do refractor telescopes have that reflectors don’t?chromatic aberration
The amount of diffraction and thus the resolution of the scope depends upon?he wavelength used and the size of the main telescope objective lens or mirror
It is diffraction that limits the ________ of a telescope’s objective.resolution
What is the resolution of a telescope?its ability to distinguish two adjacent objects close together in the sky
What is the resolving power of the telescope?the ability to distinguish adjacent objects in the sky
Which method of astronomical measurement is the precise measurement of brightness?photometry
how much better resolution would a 60 mm objective lens have than your eye’s 6 mm exit pupil?10×
Diffraction is the tendency of light to:spread around corners
It is diffraction that limits the ________ of a telescope of a given objective diameter.resolution
What are two advantages of large scopes over smaller ones?large telescopes have more light grasp and better resolution
The amount of diffraction a telescope creates depends upon:the wavelength and the diameter of the telescope objective
What type of telescope is the Hubble Space Telescope?cassegrain
The most important advantage of CCDs over film is that?they record much more light in a given exposure time
One advantage of the Hubble Space telescope over ground based ones is that?in orbit, it can operate close to its diffraction limit at visible wavelengths
The primary reason professional observatories are built on the highest mountaintops is to?reduce atmospheric blurring
What is “seeing”?a measurement of the image quality due to air stability
A mountain top is an especially good site for infrared telescopes since:All of the above are factors
What problem does adaptive optics correct?turbulence in the earth’s atmosphere which creates twinkling
What is true of radio telescopes?they have poorer angular resolution than a refractor
Which of the following is a problem inherent in all large radio telescopes?Radio waves have long wavelengths, so radio telescopes have poor resolution
Radio dishes are large in order to:increase their angular resolution and collect the very weak radio photons
In astronomy, an interferometer can be used to?improve the angular resolution of radio telescopes
Which of the following greatly improves the angular resolution of radio maps?use of interferometers
The Spitzer Space Telescope (SST) is stationed far from Earth because?Earth is a heat source and the telescope must be kept very cool
In which part of the electromagnetic spectrum have astronomers been unable to get any information?We now can access information in all spectral lengths
Which of the following is currently supplying high resolution x-ray images from space?Chandra
The design of modern x-ray telescopes depends on?grazing incidence optics
The Chandra X-ray telescope must use:grazing incidence optics to focus the short wavelengths