Related papers: Wind structure in late-B supergiants

Magnetic wind confinement has been proposed as one explanation for the complex wind structures of supergiant stars of spectral types B and A. Observational investigation of this hypothesis was undertaken using high-resolution…

Subdwarf B (sdB) stars form the blue end of the horizonal branch. Their peculiar atmospheric abundance patterns are due to diffusion processes. However, diffusion models fail to explain these anomalies quantitatively. From a NLTE model…

We provide a quantitative analysis of time-variable phenomena in the photospheric, near-star, and outflow regions of the late-B supergiant (SG) HD 199478. The analysis is based primarily on optical spectroscopic datasets secured between…

We investigate the line-profile variability (lpv) of H-alpha for a large sample of O-type supergiants. We used the Temporal Variance Spectrum (TVS) analysis, developed by Fullerton et al 1996 and modified by us to take into account the…

It is observationally as well as theoretically well established that the winds of hot, massive OB-stars are highly structured on a broad range of spatial scales. This paper first discusses consequences of the small-scale structures…

The common - arguably ubiquitous - large-scale variability of optical and UV lines profiles of hot, massive stars is widely interpreted as the direct consequence of structured, variable winds. Many of the variability phenomena are observed…

Subdwarf B (sdB) stars form the blue end of the horizonal branch (EHB). Their peculiar atmospheric abundance patterns are due to diffusion processes. However, diffusion models fail to explain these anomalies quantitatively. Weak mass loss…

We present the results of a long-term monitoring campaign of the H\alpha line in a sample of bright OB-supergiants (O7.5-B9) that aims at detecting rotationally modulated changes potentially related to the existence of large-scale wind…

A review of spectroscopic results obtained from Chandra High Energy Transmission Grating Spectrometer and XMM-Newton Reflection Grating Spectrometer observations of several wind-fed high-mass X-ray binaries (HMXBs) is presented. These…

Accurate determination of mass-loss rates from massive stars is important to understanding stellar and galactic evolution and enrichment of the interstellar medium. Large-scale structure and variability in stellar winds have significant…

Magnetic fields on hot stars can produce a variety of interesting effects on the velocity, density, and temperature structure in the winds from the stars. The fields can produce a longitudinal dependence of the mass flux, which would lead…

Many O and B stars show unexplained cyclical variability in their winds, i.e. modulation of absorption features on the rotational timescale, but not strictly periodic over longer timescales. For these stars no dipolar magnetic fields have…

We investigate the ionization structure in the non-spherical winds and disks of B[e] stars. Especially the luminous B[e] supergiants seem to have outflowing disks which are neutral in hydrogen already close to the stellar surface. The…

The Balmer lines of four A Ia - supergiants (spectral type A0 to A3) and fourteen B Ia and Ib - supergiants (spectral type B0 to B3) in the solar neighbourhood are analyzed by means of NLTE unified model atmospheres to determine the…

Data from the Canadian Galactic Plane Survey reveal an abundance of HI shells and arcs in the disk of our galaxy. While their shape is suggestive of stellar winds or supernovae influence, very few of these structures have been examined in…

Magnetic massive stars -- which are being discovered with increasing frequency -- represent a new category of wind-shaping mechanism for O and B stars. Magnetic channeling of these stars' radiation-driven winds, the Magnetically Confined…

The late stellar evolutionary phases of low and intermediate-mass stars are strongly constrained by their mass-loss rates. The wind surrounding cool evolved stars frequently shows non-spherical features, thought to be due to an unseen…

Most types of massive stars display X-ray emission that is affected by the properties of their stellar winds. Single non-magnetic OB stars have an X-ray luminosity that scales with their bolometric luminosity and their emission is thought…

Most dusty winds are described by a set of similarity functions of a single independent variable that can be chosen as the overall optical depth at visual. The self-similarity implies general scaling relations among the system parameters,…

Variable B supergiants (BSGs) constitute a heterogeneous group of stars with complex photometric and spectroscopic behaviours. They exhibit mass-loss variations and experience different types of oscillation modes, and there is growing…