We follow the interaction of massive stars with their circumstellar media over their entire lifetimes by combining several numerical models. We use a stellar evolution model for 35 and 60 M⊙ stars (Langer et al. in preparation) as inner boundary conditions for one- and two-dimensional gas dynamical models of the circumstellar medium using ZEUS (Stone & Norman 1992). In this poster, we focus on circumstellar evolution during the Luminous Blue Variable (LBV) and Wolf-Rayet (WR) stages.

We present results from a near-infrared array, CO interferometer, and H 2 O maser interferometer survey of the circumstellar environments of 26 young low-luminosity embedded stars located in nearby molecular clouds. About 75% of the sample show evidence for stellar winds/outflows in the near-infrared or CO data indicating that most of these sources are in the early wind clearing phase of their evolution. Close to 15% are multiple on the scale of 20″, suggesting that fragmentation of their surrounding dense cloud cores is important before or during gravitational collapse. Roughly 10% have H 2 O maser emission and the kinematics imply the masers arise in gravitationally unbound gas (i.e., a stellar wind or outflow) rather than in a circumstellar disk.