@inproceedings{Graefener2007,
  author    = {Gr{\"a}fener, G.},
  title     = {Clumping in hydrodynamic atmosphere models},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17925},
  year      = {2007},
  abstract  = {We investigate the effect of wind clumping on the dynamics of Wolf-Rayet winds, by means of the Potsdam Wolf-Rayet (PoWR) hydrodynamic atmosphere models. In the limit of microclumping the radiative acceleration is generally enhanced. We examine the reasons for this effect and show that the resulting wind structure depends critically on the assumed radial dependence of the clumping factor D(r). The observed terminal wind velocities for WR stars imply that D(r) increases to very large values in the outer part of the wind, in agreement with the assumption of detached expanding shells.},
  language  = {en}
}
@inproceedings{TodtHamannGraefener2007,
  author    = {Todt, Helge Tobias and Hamann, Wolf-Rainer and Gr{\"a}fener, G.},
  title     = {Clumping in [WC]-type Central Stars from electron-scattering line wings},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-17711},
  year      = {2007},
  abstract  = {While there is strong evidence for clumping in the winds of massive hot stars, very little is known about clumping in the winds from Central Stars. We have checked [WC]-type CSPN winds for clumping by inspecting the electron-scattering line wings. At least for three stars we found indications for wind inhomogeneities.},
  language  = {en}
}