Chapter 17, Problem 37E

You have enough information from this chapter to estimate the distance to Alpha Centauri, the second nearest star, which has an apparent magnitude of 0. Since it is a G2 star, like the Sun, assume it has the same luminosity as the Sun and the difference in magnitudes is a result only of the difference in distance. Estimate how far away Alpha Centauri is. Describe the necessary steps in words and then do the calculation. (As we will learn in the Celestial Distances chapter, this method-namely, assuming that stars with identical spectral types emit the same amount of energy-is actually used to estimate distances to stars.) If you assume the distance to the Sun is in AU, your answer will come out in AU.