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21 Cards in this Set
- Front
- Back
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What do optical telescopes do?
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Focus radiation received over the area to a point.
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What do refracting telescopes use?
What do reflecting telescopes use? |
Lenses
Mirrors |
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What is a light bucket?
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The collection of light over a large area
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How can you collect more radiation through a telescope?
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Have a bigger scope
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True or False. Telescopes are built to see the furthest objects in space
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False. Telescopes build large scopes in order to detect the FAINTEST objects
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What does it mean:
Light collecting power ~ area ~ D^2 |
the bigger the area, the bigger amount of particles collected
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What are the 4 types of reflecting mirrors?
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1) Prime focus telescope
2) Newtonian focus telescope 3) Cassegrain focus telescope 4) Coude focus telescope |
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Which telescope has one pick-off mirror with a side with a focus on the side of the telescope?
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Newtonian focus telescope
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Which telescope has no secondary mirror?
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Prime focus telescope
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Which telescope has a secondary mirror as well as a hole in the primary mirror (bottom)?
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Cassegrain focus telescope
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Which telescope has 2 pick-off mirrors?
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Coude focus telescope
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What is the importance in the diameter of the primary mirror in a telescope?
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collects more photons - bigger light bucket
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What does it mean that telescopes are "imagers"?
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they magnify and resolve the images
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When a telescope has a high resolution it means that it can...?
How do we achieve a high resolution? |
receive sharp resolution on images and see fine details
high resolution = low angular resolution big diameter & low wavelengths |
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Why are high altitude regions good for telescopes?
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No absorbing "twinkiling" atmosphere
Images are more clear = less atmosphere interference |
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what can travel through more material: long or short wavelengths?
What telescope is an example of this? |
Long wavelengths
contrast between: flash light cant go through a wall whereas cell reception can Spitzer space telescope |
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Why are radio telescopes big?
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Signals are weak
Wavelengths are large Frequency is small |
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What are interferometers?
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Multiple telescopes with certain distances away from each other, all working together to get the same image.
They are not very good light buckets but achieve high angular resolutions |
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How do the distances between telescopes vary in angular resolution and their ability to be a light bucket?
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The closer they are the better light bucket, but low resolution
The farther away the lower the light bucket, but very high resolution |
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Why is it beneficial to have telescopes in space?
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High altitude and lack of absorbing "twinkling" atmosphere
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How do we counteract the twinkling effect?
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Adaptive optics = 2 deformable mirrors
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