Sections Review
Video lecture for this chapter
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Vocabulary
| interferometer | light-gathering power | magnifying power |
| resolving power |
Formulae
- Light-Gathering Power =
×(diameter of
objective)2/4.
- Resolving Power
=
252,000×(observation wavelength/diameter of objective). Better resolving power has smaller
.
- Magnifying Power = (objective focal length) / (eyepiece focal length).
- Of the three powers of the telescope (light-gathering
power, resolving power, magnification) which is least important? Which
depend on the size of the objective mirror or lens?
- How many times brighter will a 60-centimeter telescope make a 10-second exposure
image than a 12-centimeter telescope?
- How many times better resolution does a 48-centimeter telescope have than a 12-centimeter
telescope?
- Will a shorter or longer wavelength enable us to see smaller details?
- Why do radio telescopes have to be so large?
- How can an interferometer be used to improve resolution?
- What is the maximum magnification that should be used with a 20-centimeter
telescope?
- Would a 30-power telescope with lens 4 centimeters across be better for observing a
faint, faraway object than a 60-power telescope with lens 3 centimeters across? Why or
why not?
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last updated:
January 19, 2022
Is this page a copy of Strobel's
Astronomy Notes?
Author of original content:
Nick Strobel