Chapter 29, Telescope Resolution Video Solutions, Pathways to Astronomy

Problem 1

If I am trying to resolve a double star with a 10 -cm diameter telescope, should I observe the star using a blue filter or a red filter? What resolution do you expect with each?

Francisco Trejo

Numerade Educator

00:21

Problem 2

What is the smallest resolvable angle of the 2.4 -m Hubble Space Telescope when it is observing 240 -nm ultraviolet light? What is its resolution when it is observing 1.2 -micron infrared light?

Khoobchandra Agrawal

Numerade Educator

01:24

Find the smallest resolvable angle of the 100 -m diameter Green Bank Telescope when it is observing radio waves at $20-\mathrm{cm}$ wavelength. What is its resolution when observing a $3-\mathrm{mm}$ wavelength?

Netra Sharma

University of Wisconsin - Milwaukee

00:58

Problem 4

Suppose that for an interferometer to work properly, the electromagnetic waves must arrive "in sync" to $1 \%$ of the period of the wave. What time difference is this for a 20 -cm wavelength radio wave? What time difference is this for a 500 -nm visiblewavelength wave? (Recall that the period of the wave is the inverse of its frequency $v$.)

Keshav Singh

Numerade Educator

01:00

Problem 5

What is the smallest resolvable angle of a radio interferometer that extends $10,000 \mathrm{km}$ when it is observing at 20 -cm wavelength? at $3-\mathrm{mm}$ wavelength?

Ben Nicholson

Numerade Educator

01:15

Problem 6

Suppose you wanted to build a telescope capable of resolving a planet the size of Earth that is 10 light-years distant.
(A) Calculate the angular diameter of Earth if it were that far away (see Unit 10.4 ). To see any detail on the surface, we would want to see an angular size about ten times smaller than this. (B) Calculate the diameter of a telescope that would be needed to resolve this angular size if observing at $500 \mathrm{nm}$. Is this feasible?

Narayan Hari

Numerade Educator

Problem 1

Problem 2

Problem 3

Problem 4

Problem 5

Problem 6