Surveying a Cluster Full Test Bank Third Edition - Understanding Our Universe 3e Complete Test Bank by Stacy Palen. DOCX document preview.
Mission 9: Surveying a Cluster
MULTIPLE CHOICE
1. Using what you know about the hydrogen-burning lifetimes of main-sequence stars, estimate the age of the globular cluster in the figure below.
a. 5 billion years d. 100 million years
b. 10 billion years e. 10 million years
c. 14 billion years
2. Which of the following stars has the hottest surface temperature?
a. M7 d. A5
b. M0 e. B8
c. F2
3. Which of the following main-sequence stars has the smallest radius?
a. M7 d. A5
b. M0 e. B8
c. F2
4. In order to directly measure the luminosity of a star from its apparent brightness in the sky so that it can be placed on the HR diagram, which of the following do you need to know?
a. mass of the star d. distance to the star
b. radius of the star e. none of the above
c. surface temperature of the star
5. The location of stars on the HR diagram give astronomers important insights about the evolutionary status and the source of energy generation in stars. What two measurable quantities determine the location of a star on the HR diagram?
a. temperature and luminosity d. mass and temperature
b. temperature and composition e. mass and luminosity
c. mass and composition
6. The Pleaides cluster
a. resides in the plane of the Milky Way.
b. is classified as an open cluster.
c. stars will drift far apart from each other over the next few billion years.
d. is known as a reflection nebula.
e. all of the above
1. The HR diagram is arguably the most important plot in the field of astronomy. It illustrates the power of relationships and classification schemes in science. By making two measurements (temperature and luminosity) and placing the star on the HR diagram, what can astronomers infer about what is powering stars?
2. What assumption do astronomers make when using the turnoff point from the main sequence to determine the age of a cluster of stars?
3. Why does the Pleiades cluster appear to have a bluish haze associated with it?