A critical test of empirical mass loss formulas applied to individual giants and supergiants

To test our new, improved Reimers-type mass-loss relation, given by Schroder & Cuntz in 2005 ( ApJ, 630, L73), we take a look at the best studied galactic giants and supergiants - particularly those with spatially resolved circumstellar shells and winds, obtained directly or by means of a companion acting as a probing light source. Together with well- known physical parameters, the selected stars provide the most powerful and critical observational venues for assessing the validity of parameterized mass- loss relations for cool winds not driven by molecules or dust. In this study, star by star, we compare our previously published relation with the original Reimers relation ( 1975, Mem. Roy. Soc. Liege 6. Ser. 8, 369), the Lamers relation ( 1981, ApJ, 245, 593), and the two relations by de Jager and his group ( 1988, A& AS, 72, 259; 1990, A& A, 231, 134). The input data, especially the stellar masses, have been constrained using detailed stellar evolution models. We find that only the relationship by Schroder & Cuntz agrees, within the error bars, with the observed mass-loss rates for all giants and supergiants.