1.
Define the Doppler Effect. Explain why astronomers use the term “blue-shifted” for objects moving toward us and “red-shifted” for objects moving away from us.
a.
2.
What is meant by “reflecting” and “refracting” telescopes? What are the differences between a Cassegrain focus, Newtonian focus, and Prime focus reflecting telescopes? Make sure to describe where detectors are located for each type of telescope.
a.
3.
How much more light can the James Webb Space Telescope (with its 6-m diameter mirror) gather than the Hubble Space Telescope (with a diameter of 2-
m)? How much more light will a 16-inch telescope collect than a 4-inch telescope?
a.
4.
The largest observatory complex in the world is on Mauna Kea, the tallest mountain on Earth. What are some factors an astronomer considers when selecting an observatory site? Should astronomers, for example, consider building an observatory on Mount Everest? Why or why not?
a.
5.
What are adaptive optics? Describe how adaptive optics can help telescopes on Earth achieve resolution comparable to Hubble Space Telescope.
a.
Extra Credit! - Optional (2 points each - Must Show work like in class to receive credit. Answers without supporting work will receive no credit.)
1.
The n = 3 to n = 2 transition of hydrogen is normally at 656.3 nm. If it is detected from a star at 652.2 nm, first argue if the star is approaching or receding, then calculate the radial velocity of the star.
2.
About how fast would you have to be driving toward a red stop-light (650 nm) for it to appear green (550 nm). To receive credit, you need to calculate using
the formula used in class. This is not a research problem!
