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Session 48 - Circumstellar Envelopes.
Display session, Tuesday, January 14
Metropolitan Ballroom,
The circumstellar envelopes B[e] stars are thought to have enhanced density near the equatorial plane. Lamers and Pauldrach (1991, Aamp;A, 244, L5) proposed that this could be produced from a "bistability mechanism" in the radiatively driven wind, by which the lower effective temperature in rotationally gravity-darkened equatorial regions leads to an abrupt shift in the wind ionization, and an associated enhanced efficiency in the radiative driving. Here we describe how this picture is modified by taking self-consistent account of the reduced radiative flux associated with the reduced equatorial effective temperature. The general result is a reduction in the equatorial density enhancement, and thus a potentially significant moderation of the net bistability effect.
