Homework Assignment #8

Name:

Section number:

Date Due: Nov. 10

1. What type of spectrum does the Sun exhibit? Explain the appearance of this spectrum by ordinary atomic processes.

2. Why do we not see helium absorption lines in the Sun's visible spectrum, even though helium is present?

3. The sun's apparent angular diameter is 0.5 degree, and its distance from Earth is about 1.5 · 108 km. Calculate the sun's true diameter in km.

4. The Sun has a mass of roughly 2 · 1030 kg. Explain (without actually doing the calculations) how this mass can be determined.

5. The Sun's radius is about 7 · 1010 cm. Given the sun's mass (in question 4), find the sun's average density in g/cm3. How does this compare to the density of water (1.0 g/cm3)?

6. The Sun's peak energy emission occurs at a wavelength of about 490 nm. Using Wien's Law, calculate the blackbody temperature of the Sun's surface in degrees K.

7. In what sense do neutrinos allow us to "see" the sun's core directly? What have been the results of the solar neutrino measurements to date?