Copernicus observations of the N V resonance doublet in 53 early-type stars

Abbott, D. C.; Bohlin, R.; Savage, B. D.

doi:10.1086/190781

Cited by 6 publications

(5 citation statements)

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“…In the spectra of most Be stars, lines from superionized ions generally do not have emission components. This same absence of emission components has been noted for 0,B stars near the main sequence (Abbott et al 1982). The absence of emission components is unexpected if lines are formed by pure scattering.…”

Section: Emission Components In Lines From Superionized Ionssupporting

confidence: 79%

Rotationally-Enhanced Stellar Winds (Review Paper)

Marlborough

1987

International Astronomical Union Colloquium

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The rotationally-enhanced stellar wind model for Be stars represents one attempt to understand many of the phenomena related to Be stars in terms of a stellar wind distorted and perhaps also enhanced by rapid stellar rotation. This review will concentrate exclusively on this particular approach; the current status of other attempts to model the circumstellar envelopes (CE) of Be stars are described in other reviews in this volume. It is assumed that Be stars are single stars; if a member of a multiple system, the separation of all components from the Be star is assumed to be sufficiently large that interactions due to mass transfer from any companion to the Be star are negligible.

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Section: Emission Components In Lines From Superionized Ionssupporting

confidence: 79%

Rotationally-Enhanced Stellar Winds (Review Paper)

Marlborough

1987

International Astronomical Union Colloquium

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“…Although the spectral-type/luminosity-class coverage is less dense than desirable, one can approximately chart the boundary in the HR diagram for the occurrence of wind profiles in O VI as follows: B0 V, 09 m, 09.5 II, 09.7 Ib, B0.5 la (with the likely possibility that the intermediate luminosity classes may extend somewhat later when further observations become available). As shown by Lamers and Snow (1978), Abbott et al (1982), and the O and B Atlases, the N v and CIV boundaries are similar or only slightly later, except that CIV wind effects persist until spectral types B3-B5 among the supergiants. The salient systematic properties of these high-ionization, high-abundance species are saturated wind profiles at all luminosity classes in the earliest spectral types, which decline toward late-O/early-B types on the main sequence, so that the wind effects then display a positive luminosity dependence at those later types.…”

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confidence: 76%

“…The most comprehensive presentations of its lowresolution (0.2 Â) observations are by Snow and Morton (1976) and Snow and Jenkins (1977). The Ovi XX1032, 1038 stellar-wind profiles observed in several stars at high resolution (0.05 Â) are discussed by Morton (1979), while the systematics of N v XX1239, 1243 are presented by Abbott et al (1982). The wind profiles in many of these spectra have been analyzed by Gathier et al (1981) and Lamers et al (1982); other detailed studies of individual stars will be cited below.…”

Section: Introductionmentioning

confidence: 99%

An Atlas of OB Spectra from 1000A to 1200A

Walborn¹,

Bohlin²

1996

PASP

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ABSTRACT. Copernicus low-resolution (0.2 Â) observations of 16 O stars, 10 B stars (mostly supergiants), and one WN-A star with the highest data quality between 1000 and 1200 Â are presented in the form of a classical spectral atlas. The purpose is to survey the systematic spectral-type/luminosity-class dependence of the line features, including those from the stellar winds, in this relatively less-studied wavelength range. Perhaps the most important new contribution is the demonstration of the pronounced luminosity effect in the S IV XX1063, 1073 wind profiles, identical to those previously recognized in Si IV XX1394, 1403 and Cm XI176, which share essentially the same ionization potential. The stellar-wind effects in O vi XX1032, 1038; P v XX1118, 1128; Si IV XX1122, 1128; and CfflXl 176 are also described. Attention is redrawn to the unidentified feature at 1099 Â, which is one of the strongest absorption lines in this range of mid-0 through early-B spectra. The atlas will facilitate interpretations of recent Hopkins Ultraviolet Telescope and future Far Ultraviolet Spectroscopic Explorer observations in this wavelength range, as well as sharpen the stellar-wind phenomenology for astrophysical analysis.

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“…cause changes in the structure of the atmosphere and wind, which strengthen the emission measure of the envelope. For example, there is evidence that supergiant OB stars have a more gradual velocity law v(r) than main sequence OB stars (Abbott, Bohlin, and Savage 1982a). From the equation of continuity, p(r) = fi/(47ir 2 v), this means that the supergiants have a higher density envelope than main sequence stars with the same rate of mass loss.…”

Section: This Results Raises a Fundamental Question About The Wolf-raymentioning

confidence: 99%

Radio Continuum Measurements of Mass Loss from Wolf-Rayet Stars

Abbott

Bieging

Churchwell

1982

Symp. - Int. Astron. Union

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The Wolf-Rayet phenomenon is defined by the striking emission line spectrum which is observed at UV, optical, and IR wavelengths. The usual interpretation is that this characteristic emission-line spectrum results from a stellar wind which has such a high density that even relatively weak lines are formed in the extended envelope formed by the outflow. This model leads to the expectation that the Wolf-Rayet phenomenon is linked to stars which have very high rates of mass loss. The purpose of this paper is to examine the relationship between the mass loss rate and the spectral appearance of O, Of, and WR stars.

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Copernicus observations of the N V resonance doublet in 53 early-type stars

Cited by 6 publications

References 0 publications

Rotationally-Enhanced Stellar Winds (Review Paper)

Rotationally-Enhanced Stellar Winds (Review Paper)

An Atlas of OB Spectra from 1000A to 1200A

Radio Continuum Measurements of Mass Loss from Wolf-Rayet Stars

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