1. A star of which spectral type has the strongest Na I absorption lines? At approximately what wavelength is this line normally found? Hint: See Figure 11-5. Figure 11-5 2. Why does a G2 star have...

1. A star of which spectral type has the strongest Na I absorption lines? At approximately what wavelength is this line normally found? Hint: See Figure 11-5.

Figure 11-5

2. Why does a G2 star have many more absorption lines than a B0 star?

3. Draw an H-R diagram and sketch the regions occupied by main-sequence stars, giants, supergiants, and white dwarfs. Briefly discuss the different ways you could have labeled the axes of your graph.