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Non-LTE analysis of the Ofpe/WN9 star HDE 269227 (R84)The paper presents the results of a spectral analysis of the Ofpe/WN9 star HD 269227 (R84), which assumes a spherically expanding atmosphere to find solutions for equations of radiative transfer. The spectra of hydrogen and helium were predicted with a non-LTE model. Six stellar parameters were determined for R84. The shape of the velocity law is empirically found, since it can be probed from the terminal velocity of the wind. The six stellar parameters are further employed in a hydrodynamic model where stellar wind is assumed to be directed by radiation pressure, duplicating the mass-loss rate and the terminal wind velocity. The velocity laws found by computation and analysis are found to agree, supporting the theory of radiation-driven stellar wind. R84 is surmised to be a post-red supergiant which lost half of its initial mass, possibly during the red-supergiant phase. This mass loss is also suggested by its spectroscopic similarity to S Doradus.
Document ID
19910050429
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Schmutz, Werner (Joint Institute for Laboratory Astrophysics Boulder, CO, United States)
Leitherer, Claus (Space Telescope Science Institute Baltimore, MD, United States)
Hubeny, Ivan (NASA Goddard Space Flight Center Greenbelt, MD; High Altitude Observatory, Boulder, CO, United States)
Vogel, Manfred (Zuerich Eidgenoessische Technische Hochschule, Zurich, Switzerland)
Hamann, Wolf-Rainer (Kiel, Universitaet Federal Republic of Germany, United States)
Date Acquired
August 15, 2013
Publication Date
May 10, 1991
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 372
ISSN: 0004-637X
Subject Category
ASTROPHYSICS
Funding Number(s)
CONTRACT_GRANT: DFG-HU-39/26-2
CONTRACT_GRANT: NSF AST-88-02937
Distribution Limits
Public
Copyright
Other