A contour plot of the percent error in M _* as a function of the percent errors in ρ _* and R _*, derived from Equation (7). We see that the dependence on ﹩{\sigma }_{{R}_{* }}﹩ is strong, and with a typical ﹩{\sigma }_{\,{\rho }_{* }}﹩ of 10%, the resulting constraint on M _* is not particularly informative. Even with no error in ρ _*, the systematic floor in R _* of ∼4.2% implies an error of 13% in stellar mass, which is much larger than the ∼5% presumed for masses derived from evolutionary models.