Related papers: Stars with the B[e] phenomenon seen by long baseli…
B[e] supergiants are luminous, massive post-main sequence stars exhibiting non-spherical winds, forbidden lines, and hot dust in a disc-like structure. The physical properties of their rich and complex circumstellar environment (CSE) are…
We report spatially resolved, spectrally dispersed N-band observations of the B[e] star Hen 3-1191 with the MIDI instrument of the Very Large Telescope Interferometer. The object is resolved with a 40 m baseline and has an equivalent…
We investigate the linear polarization produced by interstellar dust aligned by the magnetic field in the solar neighborhood (d< 50 pc). We also look for intrinsic effects from circumstellar processes, specifically in terms of polarization…
We present the results of medium resolution (Delta v = 60 km/s) spectropolarimetric observations across Halpha of a sample of B[e] and Herbig Be objects. A change in linear polarization across Halpha is detected in a large fraction of the…
In this series of papers we have presented the results of a spectroscopic survey of luminous and variable stars in the nearby spirals M31 and M33. In this paper, we present spectroscopy of 132 additional luminous stars, variables, and…
Since Be stars belong to the high velocity tail of a single B star velocity distribution, the appearance of the Be phenomenon must be independent of the stellar mass. In the present paper we show that the shape of the distribution of the…
We report the results of high-resolution ($R \sim 80,000$) spectroscopic observations of the emission-line object HD 85567, which has been classified as a FS CMa type object or a pre-main-sequence star. The main goal is to put more…
Spectral analyses of H-deficient post-AGB stars have shown that a small group of four extremely hot objects exists which have almost pure He absorption-line spectra in the optical. These are classified as O(He) stars. For their evolution…
We present the results of optical and near-IR spectroscopic and near-IR photometric observations of the emission-line stars Hen3-298 and Hen3-303. Strong emission in the H-alpha line is found in both objects. The presence of Fe II and [O I]…
Discovered over 30 years ago, the B[e] phenomenon has not yet revealed all its puzzles. New objects that exhibit it are being discovered in the Milky Way, and properties of known objects are being constrained. We review recent findings…
We give an introduction to interferometrical concepts and their applicability to Be stars. The first part of the paper concentrates on a short historic overview and basic principles of two-beam interferometric observations. In the second…
High resolution line profiles are presented for selected forbidden and permitted emission lines of a sample of galactic B[e]-type stars. The spectral resolution corresponds to 5-7 km/s with the exception of some line profiles which were…
Context: [abbreviated] Aims: Kepler data of three known Be stars are re-visited to establish their pulsational nature and assess the properties of additional, non-pulsational variations. The three program stars turned out to be one inactive…
The Be phenomenon is present in about 20$\%$ of the B-type stars. Be stars show variability on a broad range of timescales, which in most cases is related to the presence of a circumstellar disk of variable size and structure. For this…
The existence of faint blue stars far above the galactic plane, which have spectra that are similar to nearby Population I B stars, present several interesting questions. Among them are: Can a Population I B star travel from the disk to a…
Be stars have generally been characterized by the emission lines in their spectra, and especially the time variability of those spectroscopic features. They are known to also exhibit photometric variability at multiple timescales, but have…
We present the result of differential spectral analyses of a further four apparently normal B-type stars. Abundance anomalies (e.g. He, C, N enrichment), slow rotation and/or high gravities suggest that the programme stars are evolved…
Massive binaries are crucial laboratories that allow us to investigate processes occurring in quite extreme conditions, such as particle acceleration, high-energy emission, or even dust formation. All these processes are intimately…
Planet formation has been known for many years to be tied to the spatial distribution of gas and dust in disks around young stars. To constrain planet formation models, imaging observations of protoplanetary disks are required. In this…
Classical Be (CBe) stars are rapidly rotating B-type stars with Balmer emission lines that originated from the decretion disks surrounding them in their spectra. Accounting for $\sim$20% of all B-type stars, most CBe stars are thought to…