TY  - JOUR
A1  - Grassitelli, L.
A1  - Langer, N.
A1  - Sanyal, D.
A1  - Fossati, Luca
A1  - Bestenlehner, J. M.
T1  - Instabilities in the envelope of Wolf-Rayet stars
JF  - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015
N2  - Wolf-Rayet stars are very hot stars close to the Eddington limit. In the conditions encountered in their radiation pressure dominated outer layers several instabilities are expected to arise. These instabilities could influence both the dynamic of their optically thick winds and the observed spectral lines introducing small and large scale variability. We investigate the conditions in the convective envelopes of our helium star models and relate them to the appearance of a high number of stochastic density inhomogeneities, i.e. clumping in the optically thick wind. We also investigate the pulsational stability of these envelope, considering the effect of the high stellar wind mass loss rates.
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88024
SP  - 201
EP  - 204
ER  - 
TY  - JOUR
A1  - Langer, N.
A1  - Sanyal, D.
A1  - Grassitelli, L.
A1  - Szésci, D.
T1  - The stellar Eddington limit
JF  - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015
N2  - It is often assumed that when stars reach their Eddington limit, strong outflows are initiated, and that this happens only for extreme stellar masses. We discuss here that in models of up to 500 M⊙, the Eddington limit is never reached at the stellar surface. Instead, we argue that the Eddington limit is reached inside the stellar envelope in hydrogen-rich stars above ∼ 30 M⊙ and in Wolf-Rayet stars above ∼ 7 M⊙, with drastic effects for their struture and stability.
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88121
SP  - 241
EP  - 244
ER  -