A Critical Evaluation of Mass-Loss Rates and Wind Properties of Evolved Late-Type Stars

We evaluate the accuracy with which the properties of late-type giant star winds can be estimated by fitting ultraviolet line profiles and radio continuum emission. Our test cases include the stars $\alpha$ TrA (K4 II), $\lambda$ Vel (K4 Ib-II), and $\zeta$ Aur (K4 Ib + B5 V). Of particular interest is the sensitivity of the line profiles to the wind parameters Ṁ, v∞, vturb, $\beta$, and Twind. We are finding that while accurate and reliable values of Ṁ are difficult to obtain, the most reliable values come from the application of two or more independent techniques.