منابع مشابه
The Detection of Wind Variability in Magellanic Cloud O Stars
We present Far Ultraviolet Explorer (FUSE) spectra for three Magellanic Cloud O stars (Sk 80, Sk −67◦05 and Sk −67◦111) with repeated observations. The data demonstrate the capabilities of FUSE to perform time-resolved spectroscopy on extragalactic stars. The wavelength coverage of FUSE provides access to resonance lines due to less abundant species, such as sulfur, which are unsaturated in O s...
متن کاملThe Influence of Stellar Wind Variability on Measurements of Interstellar O Vi along Sightlines to Early-type Stars
A primary goal of the FUSE mission is to understand the origin of the O VI ion in the interstellar medium of the Galaxy and the Magellanic Clouds. Along sightlines to OB-type stars, these interstellar components are usually blended with O VI stellar wind profiles, which frequently vary in shape. In order to assess the effects of this time-dependent blending on measurements of the interstellar O...
متن کاملModeling Ultraviolet Wind Line Variability in Massive Hot Stars
We model the detailed time-evolution of Discrete Absorption Components (DACs) observed in P Cygni profiles of the Si iv λ1400 resonance doublet lines of the fast-rotating supergiant HD 64760 (B0.5 Ib). We adopt the common assumption that the DACs are caused by Co-rotating Interaction Regions (CIRs) in the stellar wind. We perform 3D radiative transfer calculations with hydrodynamic models of th...
متن کاملLower mass loss rates in O - type stars : Spectral signatures of dense clumps in the wind of two Galactic O 4 stars
We have analyzed the far-ultraviolet spectrum of two Galactic O4 stars, the O4If+ supergiant HD 190429A and the O4V((f)) dwarf HD 96715, using archival FUSE and IUE data. We have conducted a quantitative analysis based on the two NLTE model atmosphere and wind codes, T and CMFGEN, which incorporate a detailed treatment of NLTE metal line blanketing. From the far-UV spectrum, we have derive...
متن کاملThe superimposed photospheric and stellar wind variability of the O - type supergiant α Cam
Aims. This study seeks to provide empirical constraints on the different physical components that can act to yield temporal variability in predominantly or partially wind-formed optical lines of luminous OB stars, and thus potentially affect the reliable determination of fundamental parameters, including mass-loss rates via clumped winds. Methods. Using time-series spectroscopy from epochs spre...
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ژورنال
عنوان ژورنال: Symposium - International Astronomical Union
سال: 1994
ISSN: 0074-1809
DOI: 10.1017/s0074180900215787