6.02:  The Sun has an apparent visual magnitude of -26.75.  (a) Calculate its absolute visual magnitude.  (b) Calculate its magnitude at the distance of Alpha Centauri (1.3 pc).  (c) The Palomar Sky Survey is complete to magnitudes as faint as +19.0.   How far away (in parsecs) would a star identical to the Sun have to be in order to just barely be bright enough to be visible on Sky Survey photographs?

6.03:  (a) What is the color index (CI = B - V) of a star at a distance of 150 pc with m_V = 8.58 and M_B = 2.95? (b) Find your answer in the last column in Appendix G of the text, and give the corresponding spectral type of the star (first column of Appendix G). (c) Use the relation between CI and star temperature T, given in the lecture, to calculate the star's temperature. (d) Compare with the temperature given in the 2nd column of Appendix G, for this spectral type.