0 Assigned ID: 891 ----- Attempting Submission 1 (Fri Apr 05 22:49:38 GMT 2019) ----- Stellar winds are one of the most important factors of massive star evolution and a key ingredient in galactic chemical enrichment. Wind-sensitive UV spectral lines provide practical constraints on important stellar wind parameters. However, magnetic O- and B-type stars present line profiles with an atypical and varying shape, calling into question the accuracy of the classical massive star diagnostic toolbox for these objects. Previous work has demonstrated that magnetic wind confinement can provide a reasonable explanation for the observed UV line phenomenology, but systematic testing of this hypothesis has been severely limited by computationally expensive magnetohydrodynamical calculations. Our proposed analysis will solve this problem by applying a simple analytic prescription to efficiently calculate synthetic UV spectral lines. We are therefore able to provide better diagnostics to infer stellar wind parameters, as well as a deeper, more complete picture of the effects of large scale, global magnetic fields on stellar winds and ultimately on stellar evolution. Christiana Erba is a graduate student working with Dr. Petit, and is an expert in UV radiative transfer. Dr. Veronique Petit and Dr. Alexandre David-Uraz are experts in observational astronomy, data analysis, and computational astrophysics. They have both led successful HST observing GO proposals in the past. Stellar Physics 0 Regular false false true true false SUPPORTED