TY  - JOUR
A1  - Hamann, Wolf-Rainer
A1  - Gräfener, Götz
A1  - Koesterke, Lars
T1  - WR Central Stars
N2  - Wolf-Rayet type central stars have been analyzed with adequate model atmospheres. The obtained stellar parameters and chemical abundances allow for a discussion of their evolutionary origin.
Y1  - 2003
SN  - 1-583-81148-6
ER  - 
TY  - JOUR
A1  - Hamann, Wolf-Rainer
A1  - Gräfener, Götz
A1  - Koesterke, Lars
T1  - Wolf-Rayet star parameters from spectral analyses
N2  - The Potsdam Non-LTE code for expanding atmospheres, which accounts for clumping and iron-line blanketing, has been used to establish a grid of model atmospheres for WC stars. A parameter degeneracy is discovered for early-type WC models which do not depend on the "stellar temperature". 15 galactic WC4-7 stars are analyzed, showing a very uniform carbon abundance (He:C=55:40) with only few exceptions.
Y1  - 2003
SN  - 1-58381-133-8
ER  - 
TY  - JOUR
A1  - Gräfener, Götz
A1  - Koesterke, Lars
A1  - Hamann, Wolf-Rainer
T1  - The WR population in CTS 1026
N2  - The blue compact H II galaxy CTS 1026 shows very strong WR emission features around 4686 AA and 5800 AA. We present high S/N optical spectra of the nucleus of this object. Byanalysis of the WR profile shapes, we determine the dominant spectral types and the WN/WC ratio in the starforming region. The ratio WR/O is determined via standard nebular diagnostics.
Y1  - 2003
SN  - 1-58381-133-8
ER  -