1. Neutrinos and visible light are basically the same phenomenon, differing only in the wavelength of the radiation.
a. True
b. False
2. Merging galaxies often look blue due to star formation that is triggered by the merger
a. True
b. False
3. We believe that pulsars are
a. black holes that are spinning,
b. normal stars that oscillate (or “breath”) in and out very fast
c. neutron stars that are spinning,
d. scientists haven’t got a clue.
4. Which of these places would be a very poor choice in which to site an X-ray telescope
a. On top of a Mountain in Hawaii,
b. On the Moon,
c. In close around the Earth (i.e. just above the atmosphere),
d. In high orbit around the Earth.
5. Messier made his catalogue of nebulae because
a. he was hunting for other galaxies,
b. he was studying star formation, and needed to find potential star forming clouds,
c. he wanted to find comets and needed to catalog objects that might confuse him,
d. he built telescopes, and nebulae were good objects to test them on.
6. It is our current belief that elliptical galaxies are
a. formed when two large spiral galaxies merge together,
b. formed when a spiral galaxy merges with a small dwarf galaxy,
c. formed directly from the collapse of giant gas clouds,
d. the small fragments of a major galaxy merger.
7. [2 points] Draw a diagram of the Milky Way Galaxy. Be sure to mark and label the disk of the Galaxy, the bulge of the Galaxy, the supermassive black hole, the position of the Sun, and the Magellanic Clouds.
Grading scheme
q ½ pt for diagram of basic disk-bulge structure with labels
q ½ pt for each of
o LMC/SMC
o Position of Sun labeled
o Position of the SMBH
8. [3 points] Describe how you can use Cepheid variable stars to measure the distance to nearby galaxies. As part of your description, you should explain how the basic properties of Cepheid variable stars are “calibrated” using parallax measurements.
Grading scheme: ½ pt for mentioning each of the following:
q Cepheids are bright stars and so can be seen and studied in other galaxies
q Cepheids vary in a characteristic way
q There is a strong connection between the period of variability and the luminosity of the star.
q Once you use this relationship to determine the intrinsic luminosity of the star, you figure the distance using the inverse-square law.
q Must calibrate luminosity-period relationship of Cepheids by looking at nearby examples…
q … where you can get the distance directly from parallax measurements.