The Atmospheres of Early-Type Stars: Proceedings of a Workshop Organized Jointly by the UK SERC’s Collaborative Computational Project No. 7 and the Institut für Theoretische Physik und Sternwarte, University of Kiel Held at the University of Kiel, Germany 18–20 September 1991

Philip Dufton (auth.), U. Heber, C. Simon Jeffery (eds.)3540552561, 9783540552567, 0387552561

These workshop proceedings aim to provide a broad overview of recent developments in the study of hot stars, both from the observational and the theoretical point of view. Included are first results from the Hubble Space Telescope and ROSAT, the effects of non-radial pulsations, mass loss, magnetic fields, and diffusion, as well as modern theoretical methods to treat radiative transfer and compute model atmospheres. Many new results are described, including the discovery of a B star in the halo of M31. Together the reviews provide a general overview of hot-star spectroscopy suitable for preparing advanced lecture courses and as an introductory text for graduate students.

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Table of contents :
Galactic B-type Stars….Pages 1-10
Non-LTE analyses of B stars….Pages 11-16
Galactic B-type supergiants….Pages 17-17
On the determination of effective temperature and surface gravity using Strömgren uvbyß photometry….Pages 18-20
The mass and helium discrepancy in massive young stars….Pages 21-23
A comparison between the orbital masses of early type binary components and masses predicted by stellar evolution….Pages 24-26
B-type stars in young clusters….Pages 27-29
Chemical abundances in early B-type stars….Pages 30-32
The determination of accurate cosmic abundances from B-type stellar spectra….Pages 33-36
The origin of distant B-type stars in the galactic halo….Pages 37-40
Galactic abundance gradients from ob-type stars in young clusters and associations….Pages 41-44
Ionizing radiation from early-type stars….Pages 45-47
Abundance patterns in a stars: Carbon and silicon….Pages 48-52
Quantitative analysis of A-type supergiants….Pages 53-53
Abundances in rapidly rotating a stars….Pages 54-56
Statistical equilibrium of Al I/II in a stars and the abundance of aluminium in Vega….Pages 57-59
Analyses of B-type stars in the Magellanic Clouds….Pages 61-76
The chemical composition of main sequence stars in the Magellanic Clouds….Pages 77-80
GHRS observations of O Stars in other galaxies….Pages 81-83
The winds of hot stars in M31 and M33….Pages 84-84
Wolf-Rayet stars….Pages 85-100
Spectrophotometry of Wolf-Rayet stars….Pages 101-103
Near-Infrared Spectroscopy of Galactic Wolf-Rayet Stars….Pages 104-104
Luminous Blue Variables….Pages 105-120
Observed evolutionary changes in the visual magnitude of the luminous blue variable P Cygni….Pages 121-121
Forbidden lines of [Fe II] and [N II] in P Cygni’s envelope….Pages 122-124
Spectroscopic observational data on P Cygni and comparison with the model of the bistable wind….Pages 125-127
The spectroscopy of unusual high luminosity stars: HD 168607 and 6 Cas….Pages 128-130
Discrete absorption components in O-type stars….Pages 131-135
Analysis of circumstellar spectra of s dor….Pages 136-138
Comoving frame calculations for λ-cephei….Pages 139-141
Nonradial pulsations of O- and B-stars….Pages 143-158
Analysis of line profile variations in pulsating B stars….Pages 159-162
Mode identification of pulsating stars from line profile variations with the moment method….Pages 163-166
Mode identification in beta Cephei stars from UV observations….Pages 167-169
Magnetic fields in hot stars….Pages 170-185
The structure of Ap star magnetic fields….Pages 186-188
Diffusion, mass loss and accretion in stars….Pages 189-202
Photospheric abundances in late-A and Am-Fm stars….Pages 203-205
Effective temperature and models for early a stars: Application to 78Vir (A2P)….Pages 206-208
Silicon abundances in normal and mercury-manganese type late-B stars….Pages 209-209
Radiative accelerations on Ga and Al ions in stable atmospheres of CP stars….Pages 210-212
Si II autoionization lines in stratified atmosphere of Bp star….Pages 213-215
He – variables….Pages 216-220
Variable Hα emission in the helium-strong star δ orionis C….Pages 221-223
Lambda Bootis stars….Pages 224-227
A spectroscopic abundance analysis of Lambda Bootis stars first results in LTE….Pages 228-230
Hot subluminous stars….Pages 231-246
The spectra of blue horizontal branch stars….Pages 247-250
Weight watching in M 15….Pages 251-253
Looking for gaps….Pages 254-256
More on the progenitors of white dwarfs….Pages 257-260
Non-LTE analysis of the Palomar Green subdwarf O stars….Pages 261-263
A statistical complete sample of hot subdwarfs….Pages 264-266
NLTE analysis of a SDO binary: HD128220….Pages 267-269
NLTE analysis of helium rich subdwarf O stars….Pages 270-272
Analysis of PG 1159 stars….Pages 273-287
NLTE analysis of the hydrogen-deficient central star of the planetary nebula Abell 78….Pages 288-290
Optical observations of the ultrahigh-excitation pre-white dwarf KPD 0005+5106….Pages 291-292
The atmospheres of extreme helium stars….Pages 293-297
Mass loss from υ Sgr and other helium stars….Pages 298-300
Blue post-asymptotic giant branch stars at high galactic latitude….Pages 301-304
Old planetary nuclei and their evolutionary connections….Pages 305-309
Analysis of central stars of old planetary nebulae: Problems with the Balmer lines….Pages 310-313
Hot white dwarfs….Pages 314-328
ROSAT observations of white dwarfs….Pages 329-333
Carbon enrichment in the outer layers of hot helium-rich high gravity stars….Pages 334-336
Prospective EUVE observations of hot white dwarfs….Pages 337-339
Spectra of interacting binary white dwarf stars….Pages 340-342
The opacity project — A review….Pages 343-358
The Lyman α line wing and application for synthetic spectra of DA white dwarfs….Pages 359-361
Ion-atom complexes and the absorption of radiation in stellar plasma….Pages 362-364
Ion-atom complexes and the recombination in stellar plasma….Pages 365-367
Stark broadening parameters for spectral lines of multicharged ions in stellar atmospheres: C IV, N V, O VI lines and regularities within an isoelectronic sequence….Pages 368-370
On Stark line shifts in spectra of very hot stars….Pages 371-373
Accelerated Lambda Iteration….Pages 375-392
Instabilities in hot-star winds: Basic physics and recent developments….Pages 393-408
Radiation-driven wind theory: Not (yet?) working….Pages 409-413
Radiation-driven wind theory: The influence of turbulence….Pages 414-416
Application of the etla approach in the comoving frame to the study of winds in hot stars….Pages 417-419
Interactive LTE spectrum synthesis….Pages 420-424
Calculations of line positions in the presence of magnetic and electric fields in white dwarf spectra….Pages 425-427
Treatment Of strong magnetic fields in very hot stellar atmospheres….Pages 428-430
Blends, frequency grids and the Scharmer scheme….Pages 431-434
Multilevel non-LTE radiative transfer using exact complete and diagonal operators….Pages 435-435
Iron line blanketing in NLTE model atmospheres for O stars: First results….Pages 436-439
Calculations of non-LTE radiative transfer in extended outflowing atmospheres using the Sobolev approximation for line transfer….Pages 440-444
3d radiative line-transfer for disk-shaped be star envelopes….Pages 445-447