Spelling suggestions: "subject:"O start."" "subject:"O stark.""
1 |
The formation of late O and early B stars within dense molecular cloudsBeichman, Charles Arnold January 1979 (has links)
Photocopy of typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1979. / Bibliography: leaves 127-138. / Microfiche. / x, 138 leaves ill., maps 29 cm
|
2 |
The distribution of O and early B stars, gas and cosmic dust across the Carina spiral featureMiller, Ellis Wilson, 1939- January 1971 (has links)
No description available.
|
3 |
X-Ray Line Emission from Weak Wind O-StarsHuenemoerder, David, Oskinova, L., Hamann, W., Ignace, Richard, Todt, H., Waldron, W. 01 January 2011 (has links)
The action of X-rays is commonly invoked to explain the wind properties of low-luminosity O-type stars. These stars have significantly smaller mass loss rates than predicted radiation-driven wind theories. In this respect they may resemble the first generation of supermassive stars in the early universe which presumably had weak winds due to their low metallicity. We present the high-resolution X-ray spectrum of a weak-wind star, mu Col, and discuss the potential for X-ray emission line strengths and profiles to discriminate among proposed mechanisms for the generation of X-rays in stellar winds, and in resolving the weak-wind problem.
|
4 |
Magnetic field measurements of O stars with FORS 1 at the VLT.Hubrig, S., Schöller, M., Schnerr, R., González, J., Ignace, Richard, Henrichs, H. 01 November 2008 (has links) (PDF)
Context.The presence of magnetic fields in O-type stars has been suspected for a long time. The discovery of these fields would explain a wide range of well documented enigmatic phenomena in massive stars, in particular cyclical wind variability, Hα emission variations, chemical peculiarity, narrow X-ray emission lines, and non-thermal radio/X-ray emission. Aims.To investigate the incidence of magnetic fields in O stars, we acquired 38 new spectropolarimetric observations with FORS 1 (FOcal Reducer low dispersion Spectrograph) mounted on the 8-m Kueyen telescope of the VLT. Methods.Spectropolarimetric observations were obtained at different phases for a sample of 13 O stars. Ten stars were observed in the spectral range 348−589 nm, HD 36879 and HD 148937 were observed in the spectral region 325−621 nm, and HD 155806 was observed in both settings. To prove the feasibility of the FORS 1 spectropolarimetric mode for the measurements of magnetic fields in hot stars, we present in addition 12 FORS 1 observations of the mean longitudinal magnetic field in θ1 Ori C and compare them with measurements obtained with the MuSiCoS, ESPaDOnS, and Narval spectropolarimeters. Results.Most stars in our sample, which were observed on different nights, show a change of the magnetic field polarity, but a field at a significance level of 3σ was detected in only four stars, HD 36879, HD 148937, HD 152408, and HD 164794. The largest longitudinal magnetic field, Bz = −276 ± 88 G, was detected in the Of?p star HD 148937. We conclude that large-scale organized magnetic fields with polar field strengths larger than 1 kG are not widespread among O-type stars.
|
Page generated in 0.0544 seconds