Problem set due in class, Apr 16. Show your work, neatly.

1) Calculate the M/L for the stars in a typical cubic parsec in the solar neighborhood. Comment on the stars that contribute most of the mass and most of the light. Delete all stars regarded as `young', i.e. early than type G. How does M/L change?

You will need:

1) luminosity function, i.e. the number of stars per parsec^3 as a function of luminosity

2) the mass-luminosity relation for MS, to convert luminosity into mass

3) number of stars that are evolved versus main sequence as function of luminosity

The procedure is to sum up the number of stars per luminosity, then do the same sum as mass. Note that you have to divide the problem into main sequences stars and giant (evolved) stars and sum the two categories. Assume that all giant stars are 1.2 solar masses regardless of luminosity (why?). Show all your work/steps.