|
|
Paper: |
The Envelopes of B[e] Stars |
Volume: |
355, Stars With the B[e] Phenomenon |
Page: |
39 |
Authors: |
Hillier, D.J. |
Abstract: |
Our current understanding of B[e] envelopes, obtained through a variety of techniques including spectral studies, polarization studies, and interferometric studies, is summarized. While the hybrid spectra of B[e] stars strongly suggests the presence of a dense equatorial zone (or disk), and a more normal stellar wind, accurate knowledge of the density and velocity structure of the envelope is still lacking. We highlight the importance of using reflection nebula, which can allow us to look at the illuminating B[e] star from a different direction, to provide additional geometrical constraints on the B[e] envelope. Radiation pressure is expected to play a key role in formation of the envelope, but the actual “disk” generating mechanism has not yet been identified. Four mechanisms for disk formation are discussed: the bistability mechanism, wind-compressed disks, centrifugal ejection, and magnetic fields. |
|
|
|
|